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103325
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Martin
The friendly stars
68-093^1
THE
FRIENDLY STARS
A New Edition of an Astronomical Classic
Martha Evans Martin
And
Donald Howard Menzel
With New Illustrations by
CHING-SUNG YU
Professor of Astronomy , Hood College
And a Foreword by
DONALD HOWARD MENZEL
and
WILLIAM W. MORGAN
Former Director, Yerkes Observatory
DOVER PUBLICATIONS, INC., NEW YORK
Copyright 1907,1954 by Elizabeth J. Evans.
Copyright 1964,1966 by I>over Publications,
Inc.
All rights reserved under Pan American and In-
ternational Copyright Conventions.
Published in Canada by General Publishing Com-
pany, Ltd., SO Lesmill Road, Don Mills, Toronto,
Ontario.
Published in the United Kingdom, by Constable
and Company, Ltd., 1O Orange Street, London
W. C. 2.
This I>over edition, first published in 1964, is a
revised and enlarged version of the work first pub-
lished by Harper & Brothers in 19O7.
ZJ&rary of Congress Catalog Card Number;
Manufactured in the U.nited States of America
Dover Publications, Inc.
ISO Varick Street
New York 14, N. Y.
Foreword
This is a charming book, a book that brings us close to
the starry night and other aspects of Nature that appeal to
our senses. It is a Nature book in the most popular sense;
it is not a book for the technical student.
And yet, The Friendly Stars was an important influence in
the decision of two boys (living in widely separated places)
to become astronomers, some forty years ago. The interest
and excitement it generated were among the principal causes
for our deciding to devote our lives to discovering more about
the stars and the universe.
In the past we have frequently recommended The Friendly
Stars to other young people and have regretted that it has
long been out of print as well as in need of revision. This
new, revised edition, we believe, fills a gap in the literature of
elementary astronomy.
1963 DONALD H. MENZEL
Harvard College Observatory
WILLIAM W. MORGAN
Yerkes Observatory
Acknowledgments
In revising The Friendly Stars I have tried, as far as possible,
to retain the informal style of the original author, Martha
Evans Martin. Major revision has been necessary only in the sec-
tions related to the physical characteristics of the stars: distances,
velocities, temperatures, and evolutionary stages. I have also
introduced the results of historical studies that I have personally
made in the origin of the major constellation figures.
On the rare occasions where I differ with Mrs. Martin,
I have expressed her viewpoint even when I may hold an-
other. Our major point of disagreement concerns the relative
importance of the stars and constellations; Mrs. Martin finds
the star groups and constellation figures uninteresting, unimag-
inative, and hard to see. I believe that the constellation forms
have evolved imaginatively from early times. When properly
drawn, they are helpful guides to recognition of the various
star groups. The figures here employed differ significantly from
those given in the original edition of The Friendly Stars. They
are identical with those I devised for Field Guide to the
Stars and Planets.* Many of these figures are based, in turn, on the
imaginative diagrams designed by H. A. Rey, in his book The Stars
A New Way To See Them? I am indebted to Mr. Rey and to
Houghton Mifflin Company for permission to employ these fig-
ures in this book.
I also wish to acknowledge the excellent art work of Ching-
Sung Yii. Dr. William W. Morgan, whose interest in this book
encouraged the revision, not only joined me in preparation of
a Foreword, but also kindly read the manuscript and made
many helpful suggestions. I sincerely hope that young amateur
astronomers, the world over, will find this new edition of The
Friendly Stars interesting and stimulating.
D.H.M.
*Field Guide to the Stars and Planets by Donald H. Menzel. Published by
Houghton Mifflin Company. Copyright 1963 by Donald H. Menzel.
\The Stars A New Way To See Them by H. A. Rey. Published by Houghfon
Mifflin Company. Copyright 1952 by H. A. Rey.
wi
Contents
chapter
INTRODUCTION
I THE RISING AND THE SETTING OF THE STARS
II CONCERNING THE BRIGHTEST STARS
III CAPELLA
IV ARCTURUS
V SPICA
VI VEGA
VII DENEB
VIII ALTAIR
IX ANTARES
X FOMALHAUT
XI ALDEBARAN
XII ORION'S BRIGHT STARS
XIII THE HEAVENLY TWINS
XIV THE Two DOG STARS
XV REGULUS
XVI THE NUMBER OF THE STARS
XVII THE NAMES OF THE STARS
XVIII THE LIGHT OF THE STARS
XIX THE DISTANCES OF THE STARS
XX DOUBLE STARS
XXI THE CONSTELLATIONS
XXII THE LITTLE BEAR AND POLARIS
XXIII THE GREAT BEAR AND THE SEVEN STARS OF THE DIPPER
XXIV CASSIOPEIA, CEPHEUS, AND THE DRAGON
XXV FROM THE HUNTING-DOGS TO THE ARROW .
XXVI FROM THE WINGED HORSE TO THE BULL
XXVII THE MYSTERY OF THE PLEIADES
XXVIII FROM THE TWINS BACK TO THE HUNTER
XXIX CONSTELLATIONS WHOLLY OR IN PART
SOUTH OF THE EQUATOR
XXX INDIVIDUALITY OF THE STARS
INDEX
page
1
5
10
17
20
24
26
30
35
40
45
48
52
57
61
66
70
74
78
84
91
98
101
104
108
111
116
124
129
131
139
143
Illustrations
page
THE BIG DIPPER 15
RELATIVE POSITION OF THE NORTH STAR AND THE DIPPER . . 14
VEGA (IN LYRA) AS SHE APPEARS IN THE EAST .... 27
VEGA AND HER ATTENDANT STARS IN THE NORTHWEST ... 28
TRIANGLE FORMED BY POLARIS, DENEB, AND VEGA . . . 31
THE NORTHERN CROSS, PART OF CYGNUS, THE SWAN ... 32
ALTAIR AND ITS Two COMPANIONS IN AQUILA .... 36
DENEB, ALTAIR, AND VEGA 37
THE DOLPHIN (DELPHINUS), OR JOB'S COFFIN .... 38
SCORPIUS 41
FOMALHAUT 46
THE HYADES 49
ORION 53
THE SICKLE 67
THE LITTLE DIPPER 103
THE SEVEN STARS OF THE BIG DIPPER 105
CASSIOPEIA 109
HERCULES 113
ANDROMEDA, THE SQUARE OF PEGASUS, ,
AND THE SEGMENT OF PERSEUS 118
THE PLEIADES 125
LEO OR THE LION . 130
LIBRA OR THE SCALES 132
SAGITTARIUS OR THE MILK DIPPER 133
PLATE I NORTH CIRCUMPOLAR STAR CHARTS . . inside back cover
PLATE II EQUATORIAL STAR CHARTS .... inside back cover
Introduction
chief aim of this book is to share with others the
* pleasure that the writer has had in what may be called
a relation of personal friendship with the stars. In this rela-
tion one knows the more conspicuous stars by name and at a
glance; and is able to greet them as pleasant acquaintances
when they return year after year in the due seasons, or each
evening as they pass over their prescribed paths serene and
stately, or dancing and twinkling, according to their several
habits.
One has a fine sense of companionship with the stars when
, he has secured this kind of acquaintance with them when on
looking out of the window at any hour of the night he can
see a familiar face twinkling at him as if in friendly recogni-
tion of the fact that he must know it is due at that hour and
is expecting to see it; or when, on a cold midnight in late
February, before the trees and birds have announced the spring-
time, he sees a bright, bluish, scintillating point just pushing
up over the eastern horizon and knows that Vega has come to
grace the skies again and that spring will surely come with her.
Such a feeling for the stars is not induced by exciting jvon-
der at the expanse and mystery of the^heayens^ or by burden-
ing ^uad. oppressing the mind with the vastness that seems
beyond all compassing in thought, but by showing how the stars,
like the flowers and the trees, are but parts of the visible beauty
of nature which have their share in making "the perfect whole."
Plants and birds come in their turn
As the revolving seasons rise
Above the tree-tops star by star,
and the steady advance of the changing season gets a definite-
ness and an interest to one otherwise impossible when he has
learned to associate the visible signs of the progress of the year
2 The Friendly Stars
as they appear in the skies as well as on the earth. He will then
associate tne blooming of the blood-root and the first warble
of the bluebirds with the eastern splendor of Arcturus and the
blooming of the maples. When he watches in the daytime for
the first blue violets he will look the same evening for the
blue twinkling face of Vega. He will know that the j uncos and
Sirius leave us at about the same time in the spring; that when
the golden-rod and the wild asters are blooming it is time to
look for Fomalhaut and that Antares is about to go; and a
creaking, frosty night will make him involuntarily turn his
eyes up to mighty Orion striding across the southern skies.
Such things as these, which are so dear to the heart of the
lover of nature, are not learned as one learns a lesson, or by
the being told, but by coming into a personal relation, a rela-
tion very easily established by one who really desires it, with
the flowers and trees and birds and stars, knowing them all in
their seasons and their associations.
For such knowledge as this no technical information is nec-
essary, though it may be followed by a desire for technical
knowledge. The two are quite different things. But one can
come to no real appreciation of anything in nature without
some knowledge of particular objects. The acquirement of it is
just as important and just as easy with the stars as with the
flowers. One may revel in the beauty of a whole field of grass
and flowers, but his heart gives a leap when he sees among
them the face of some flower that he knows and likes, and he
cries, "There's a lily," or a gentian, or whatever it may be.
Birds may flit around us as we sit in the woods, and we note
them as blade, yellow, pretty, or whatever, and we think we
are getting all the pleasure we can from them; but interest
quickens when one comes that we can name, and it at once
has an individuality and an importance that none of the rest
have.
So it is with the stars: a starry night is beautiful and we
gaae at it and enjoy it and do not care to know more about it
in detail. But if by chance we come to know by name one bright
star, it immediately separates itself from all the others and be-
comes an individual. If we enlarge our acquaintance in the
skies, the whole aspect of the heavens is changed, and, instead
of a brilliant assembly of impersonal points of light, we see
Introduction 3
a host of individuals that we know as bright Capella, sombre
Betelgeuse, and others.
And this satisfaction we may secure without troubling about
meridians and ecliptics, or right ascension and declination, or
any other of the scientific trappings of the stars, just as we have
it with the flowers without attending to sepals and petals, or
pistils and anthers, and with the birds without any thought of
anatomical classification. The only thing one needs to do in
order to have such an acquaintance with the stars is to look
for them: and this book aims to show how and when and where
to look for them in the easiest possible way.
Any especially scientific information will be omitted, the de-
sire being to make the stars as interesting in themselves as pos-
sible and to show how simple a matter it is to know in an
intelligent but untechnical way the choicest individuals among
them, the leading facts concerning them, their bearing in prac-
tical life, and all that is individually beautiful and important
about them. This, it is believed, will yield a pleasure such that
any one who has once experienced it will receive a very large
reward for the small labor entailed.
It is by no means a dry and difficult thing to acquire any
particular knowledge of the stars. One, if rightly directed, will
find on pursuing the subject only just a little way that, while
giving himself next to no trouble about it, he can soon come
to know the more notable ones by name and to have a fair
fund of practical information about them. Many of the stars,
which now all look so much alike to him, will have acquired
such an individuality that he can recognize them at a glance
in whatever position in the skies he may see them. And he
will find, too, that the pleasure one never fails to have in the
spectacle of the whole sky is multiplied many times for him as
soon as he knows something of the individuals that make up
this splendid panorama.
It is an interesting fact that the stars as individuals figure a
great deal more prominently in old than in modern literature,
and the writers of the older literature show a more personal
acquaintance with them than the writers of the later literature
show. This intimate knowledge of the stars really preceded the
science of astronomy. The stars were better known even to peo-
ple at large before there was any such science than they are
4 The Friendly Stars
known now, and there is only too much justice in Emerson's re-
proach that now, in these days of nautical almanacs, "the man
in the street does not know a star in the sky. The solstice he
does not observe, the equinox he knows as little; and the whole
bright calendar of the year is without a dial in his mind."
The explanation of this difference is that people in earlier
times, being more out of doors than the people of the present
day, were more observant of out-door objects and took more
interest in them. For it is, after all, mainly a matter of obser-
vation; and for learning to know the leading stars and getting
the interest that attends an acquaintance with them, little more
is needful than simply looking at them. It is looking at them,
too, with only the naked eye; for all the stars that attract spe-
cial notice and have individual names were noticed and so
named long before the invention of the telescope; and the prin-
cipal constellations were traced and named by simple shepherds
who tended their flocks at night in the open fields and had
nothing to aid them but their own eyes and fancy.
I
The Rising and the Setting of the Stars
HP HE most favorable time for identifying a star is when it is
A rising, or has just risen, especially if its rising takes place
anywhere between twilight and midnight, the portion of the
day most likely to be convenient for observers. It is then in the
eastern part of the sky, where the afterglow of the sunset does
not dim its luster, and it is far enough down towards the ho-
rizon for one to look at it face to face in a comfortable atti-
tude. Moreover, at rising, a star is more nearly by itself, more
separated from neighboring stars, and is, therefore, much more
easily recognized than when one has to pick it out from among
the host of other stars already scattered over the sky and in as
plain view as it. For near the horizon the atmosphere obliter-
ates the multitude of faint stars that are plainly visible higher
up in the sky.
It is true that, owing to the density of the atmosphere there,
all stars twinkle more, and hence shine with less steadiness,
when they are near the horizon than when they are higher up
in the sky, and most stars are not to be seen at all until they
have actually risen some distance above the horizon. Then there
is to be allowed for, the interference of buildings, trees, and
other objects in the landscape; but, even in spite of these in-
terferences, most any star comes well into view before it has
risen so high that it cannot be easily separated from the others
and looked at with comfort. One has the advantage given by
the comparative isolation of a rising star whether it rises from
below the horizon or from behind the trees and houses.
If one were observing a star through a telescope and for other
purposes than that of identification, he should choose, as nearly
as possible, a time when the star is in the middle of its course
from east to west, or as nearly overhead as it ever reaches. There
6 The Friendly Stars
the atmosphere will be clearer and, in consequence, the star will
shine with a steadier light and offer less opportunity for optical
illusions. But this means either a neck-breaking attitude or some
special preparations for a comfortable reclining posture, either
of which is more or less discouraging to one who has not al-
ready become pretty familiar with the stars. When he has come
to know them, there is no greater delight than to lie stretched
on a cot in the open with the whole expanse of the heavens
above him, and watch them as they rise and pass and go again.
This is the stage of acquaintance that binds one forever in
friendship with the stars. But a speaking acquaintance may be
maintained that will give much pleasure with lighter demands
upon one.
The rising of the stars is the time of recognition and greet-
ing. But it is no less important to speed the parting guest; and
the next most satisfactory time to watch a star is when it has
readied the western sky and is about to leave us until it comes
again to the eastern door on its never-ceasing round. Here,
while the star remains the same in its individual attributes, all
its setting is the reverse of what it was when the star first ap-
peared above the eastern horizon. The parallelogram of twink-
ling stars that trailed behind Vega as she rose in the east now
waves above her as she sinks below the line of vision in the west.
The Northern Cross, which heaved itself into sight in the east
almost wrong-side up, with Deneb weighting the head of it,
has, twenty hours later, practically righted itself and is lost to
view in the glowing west with Deneb dancing on the tip of its
upright. So complete identification must include the recogni-
tion of a star both in the east and in the west.
In the north the stars that constantly circle around the pole
are always visible to us. They complete their small round once
in twenty-four hours,- but their path lies entirely above the ho-
risofi, so they never rise or set. Within this circle are the Pole
Star and the stars of the Great Dipper, which will be illustrated
is the next chapter; but it includes none of the brightest stars.
Next comes a line of stars describing a larger circle around
Ae pole, one that takes them below the horizon for a longer or
shorter time according to their distance from the pivotal point,
the pole. These stars rise in the northeast, make a long, slow
sweep of the sky, and set in the northwest, finishing their circle
The Rising and the Setting of the Stars 7
below the horizon and rising not long after they set. Among
these are some of the brightest stars.
Then follows a belt of stars that rise somewhere near the
exact eastern point of the horizon, cross the heavens to the west-
ern point in about twelve hours, and remain below the horizon
another twelve hours.
And, finally, there are the stars in the southern section of the
sky, which rise south of east and set in the southwest, never ris-
ing very high in the heavens, the portion of their circle, or
course, over which we can see them pass being smaller and
smaller as that course lies farther and farther south of us. Among
these southern stars are Sirius, the star that outshines all the
others, and Fomalhaut, which hides from us for sixteen hours
out of each twenty-four.
All the stars that rise south of the exact eastern point on the
horizon are called southern stars; for the sky is divided into a
northern and a southern hemisphere by an equator running
half-way between the north and the south pole, just as the earth
is divided. The northernmost stars of the southern hemisphere
are visible to us just as the southernmost stars of the northern
hemisphere are visible to people living in southern latitudes.
These distinctions are of no great importance, but it is well to
understand that, while we cannot see the southern stars as a
body, yet some of them are visible to us and still are spoken
of as southern stars. Three of the brightest stars that come
within our view, Rigel, Antares, and Spica, are southern stars,
in addition to Sirius and Fomalhaut, which have already been
mentioned.
Unlike the sun and moon and the planets, each star rises
always at practically the same point in the heavens. It comes
back to the starting-point each day four minutes earlier than
the day before, which makes it rise about an hour earlier each
fortnight, and two hours earlier each month; so that in twelve
months it comes back twenty-four hours earlier. This brings it
back to the same rising point at almost the same second once
a year.
These changes from day to day in the time of the rising and
the setting of the stars are regular and definite; and so it is an
easy matter, after one has once learned to recognize a star,
either by its appearance or its surroundings, to know where to
$ The Friendly Stars
look for it at any given date. If a star, for instance, is due to
rise at six o'clock in the evening on the first of March, it will
rise at four in the afternoon in April, and at eight in the eve-
ning in February; at two o'clock in the afternoon in May, and
at ten in the evening in January; at noon in June, and at mid-
night in December; and so on throughout the year. Hence, al-
most any star can be seen at some time in the night for six months
in the year. The other six months, if it is among the northern-
most stars, it can be seen more or less each night; but if it is
among those that are below the horizon many hours, it may be
above it during the hours of sunshine and thus be rendered in-
visible to the naked eye, though even in the daytime one can
usually find a bright star with a telescope.
The times of rising and setting given in this book are for
about the latitude of New York City, which is nearly forty-one
degrees north latitude. For any place within five degrees of this
latitude on either side the difference in time of rising is so
slight that for mere purposes of identification it will not matter.
The time of the appearance of the stars to persons within this
belt of latitude is the same all the way across the country from
Maine to California. It includes the region around all the large
cities of the Eastern and Middle States and most of the Western
ones. Within it lie Portland, Boston, Philadelphia, Washing-
ton, Baltimore, Cincinnati, Indianapolis, Chicago, St. Paul,
Detroit, Louisville, St. Louis, Denver, and San Francisco. On
the southernmost edge of it is Memphis, and just a little out-
side of it on the north is Olympia, Washington. Los Angeles
lies a little outside it on the south. Above or below this belt
one must take latitude somewhat into consideration; which
means only to remember that when an observer is placed farther
south the stars to the north of him rise somewhat later and
those to the south of him somewhat earlier, and that if he is
placed north of this belt the stars to the south of him rise some-
irfiat later and those to the north of him somewhat earlier.
The rising-times of the stars as given here will answer approxi-
mately for any place in the United States.
When the rising-time of a star is referred to in these pages,
k is usually given as nearly as possible in round numbers to
avoid any complications, If the actual time, for instance, is 6:55,
it is given as 7:00. Variations of this kind seldom extend over
The Rising and the Setting of the Stars 9
more than a few minutes and they more often give a time a
little later instead of earlier than the exact minute. This makes
the inexactness still more immaterial, since for naked eye ob-
servation one cannot hold the stars to their scheduled minute
of rising, and anywhere within half an hour is a reasonable ex-
pectation in that regard. They are there, to be sure, but varia-
tions of climate between two places and variations of atmosphere
from day to day will make a considerable difference in their visi-
bility when near the horizon. After they are well up in the sky,
of course, one need not make so many concessions.
The times quoted are strictly standard times for the selected
meridian. For sites to the east or west of the standard meridian
the time will differ. Also for daylight saving time, remember to
add one hour.
It is to be remembered also that one is rarely ever situated
where he can really see the horizon, but owing to various causes
sees usually a line somewhat above the true horizon.
II
Concerning the Brightest Stars
A MONG the hundreds of thousands of stars in the universe
there are twenty-one that are so much brighter than the oth-
ers as to make a class by themselves. They are known as stars of
the first magnitude, or highest degree of brightness. These
twenty-one stars are so scattered over the sky and each so dom-
inates the section in which it is found, that if one comes to know
them, there is no quarter of the heavens towards which he can
turn his eye and not have a pleasant sense of familiarity with it.
Each one of these stars has a fixed place in the sky, and all
but three have proper names of their own. The stars in general
are not known by individual names; so it is a matter of congratu-
lation that nearly all the bright ones are so known, and espe-
cially that this is true of all the brightest stars that can be seen
in our latitude. The fixed place they have in common with all
the other stars, which, when once their place is known, can al-
ways be found in the same spot. For the stars are steadfast.
Spring, summer, autumn and winter each has its own bright stel-
lar setting, and we can always count on its appearing with un-
changing beauty and unfailing promptness. The moon comes
and goes. She is the symbol of inconstancy. The planets wander
from place to place-most of them easy enough to find, but con-
tinually changing in brightness and position. Only the stars
are always the same.
The names of the twenty-one brightest stars, given in the order
of their brightness, are as follows:
pronounced SirM-us
n'tauri':::::::::;:;;;;; ....... : ^g *
Arcturus ...... ....... ^! & Sen-td
Vega ........................ Ark-tu'-rus
Concerning the Brightest Stars 11
Rigel
Procyon
Achernar
Beta Centauri
Altair
Betelgeuse . . .
Aldebaran . . .
Alpha Crucis
Spica
Antares
Pollux
Fomalhaut . . .
Re'-jel, or Ri'-jel
Pr6'-si-on
A-ker'-nar
Ba-ta Sen-ti'-re
Al'-tare
Bet'-el-gerz
Al-defr-a-ran
Al-fa cru'-sis
Spi'-ka
An-ta'-rez
Pol'-uks
F6'-mal-o
Deneb " Den'-eb
Beta Crucis " Ba-ta cru'-sis
Regulus " Reg'-u-lus
There are six stars among the twenty-one brightest which are
so far south that they cannot be seen in our latitude. But they
are important and beautiful, and it may be worth while to
speak of them briefly before we pass on to the others of this
bright company with whom we hope to have a friendly ac-
quaintance. These six stars are Canopus, Alpha Centauri, Beta
Centauri, Alpha Crucis, Beta Crucis, and Achernar. In some
parts of Florida and Texas, Achernar can be seen low in the
south for a short time in the evening, and Canopus, which is a
little farther north, can be seen a somewhat longer time and
higher up in the sky. All six of these stars can be seen in Cuba.
It is to be regretted that they must remain hidden from us, for
there are special reasons why some of them would interest us,
aside from their great beauty.
Canopus, for instance, is far brighter than any star visible in
the northern hemisphere save one, the brilliant star Sirius, and
Canopus is so much farther away than Sirius that it must be
many times brighter and really radiate many times more heat
and light. Canopus is, in fact, one of the brightest stars in our
galaxy; for all its superior brilliancy, it is so far away that light
requires 230 years to reach us. Sirius, though it outshines
Canopus to our view, is comparatively near since light takes only
seven years to reach us.
Incidentally, it may be interesting to know that Canopus is
credited with having run away with one of the Pleiades. If he
did the deed, he has succeeded in concealing the proof of it, for
the lost Pleiad has never been seen elsewhere since she was re-
puted to have disappeared from her place among her six sisters.
12 The Friendly Stars
Alpha Centauri is distinguished as being, so far as is now
known, the nearest star to us with the exception of our sun. It
is not near enough for any inconvenient neighborliness, as we
shall find later on; Alpha Centauri, itself a double star, has a
third, fainter component, possibly slightly nearer than Alpha.
This faint companion star is sometimes called Proxima; but
the name has not come into any general use, nor does it seem
very desirable that it should. For all our feeling that so impor-
tant a star ought to have an individual name, Proxima does not
seem the right choice. It may well be that in the course of time
other stars will be found to be nearer to us than Alpha Centauri,
and the name would then have no appropriateness. Alpha Cen-
tauri also bears the name Rigil Kent.
Beta Centauri, sometimes called Hadar, is a brilliant star, not
quite so bright as Alpha. The two stars lie very near together.
The distance between them is about four degrees. This is a
little more than the distance between Castor and Pollux and
not quite so much as that between the two pointers in the
Dipper. Alpha Crucis, almost as bright, lies not far away, and
the three stars make a brilliant spectacle in the southern sky.
Achernar, but little fainter than Alpha Centauri in brightness,
is the only very bright star in its section of the southern heavens.
The other sixteen of the brightest stars are all visible to us,
and are the ones we shall seek to know first. After they are well
identified it will be easy to point out others, less brilliant, but
perhaps not less significant.
To find any of these stars only two things are necessary to be
known as a basis from which to work: the constellation known
as the Big Dipper, and the North Star (Polaris is its name) .
In the strictest sense, the Big Dipper is not a constellation at
all, but an "asterism," a group of stars that forms part of the
laige constellation, the Greater Bear. The Big Dipper consists
of sevea principal stars, all very bright, but none of them among
tfce twenty-one brightest, grouped so as to resemble the outline of
a dipper.
This star group is so conspicuous and, hence, so easy to find,
that it is known to most persons. The Big Dipper is one of the
few star patterns that really look like the things after which
they are named. It lies in the northern heavens, and in our lati-
tude is above the horizon all night, so that it can always be seen
Concerning the Brightest Stars
14 h
4-60
13 h 12 h +50 11"
THE BIG DIPPER
when the skies are clear. The two stars on the outer side of the
bowl are called the "pointers," because a line drawn through
them from bottom to top will point towards the North Star,
and, if extended to about five times the distance between the
two stars, will end, not exactly, but yet so nearly at Polaris
that there will be no mistaking the star.
The North Star marks the center, or pole, around which the
celestial sphere revolves, and the pointers always hold the same
relative situation to it no matter how the dipper is turned with
relation to us. The North Star and the Dipper as they appear
to an observer on the earth in our latitude at the different
seasons of the year have the relative position shown in the
illustration.
Inasmuch as all the stars seen in the northern hemisphere of
the heavens revolve around the point marked by the North
Star, their positions relative to one another are always the same.
So if one bears this in mind, it will be just as easy to find them
at one time in the year, or in the evening, as at another. The
positions given in the diagram of the Dipper are as the stars
composing it appear early in the evening at the seasons named.
They make a circuit of the pole each twenty-four hours, so that
if one watches all night he can see them in at least three of these
positions each night in winter and in two of them during the
short nights of summer. Into the other positions they come, of
course, in the daytime.
14
The Friendly Stars
NORTH HORIZON
RELATIVE POSITION OF THE NORTH STAR AND THE DIPPER
The distance between the two pointers is about five degrees;
and this is an important thing to keep in mind. These known
ive degrees may be used as a unit of measure in finding other
stars as described in this book. If one cannot carry the distance
between the pointers hi his mind from one part of the skies to
aoodier and thus make comparisons of distances that will be
approximately correct, he can take a stiff piece of card-board,
or an adjustable ruler, and, holding it out at arm's-length, adjust
it so as to exactly cover the space between the two pointers. He
will then have a fairly accurate measure of five degrees in the
Concerning the Brightest Stars 75
sky and will probably be surprised to find that it will require a
little less than three inches on his ruler to cover it. This will be
of great assistance in marking off approximate distances on the
surface of the heavens as it appears to us, and will enable one
to follow the directions given in these pages. It will be a still
further convenience to make a measure from two to four times
as long, thus covering ten or twenty degrees. In adjusting these
measures it will be found necessary to sight with one eye only,
keeping the other closed. One cannot cover a star from both
eyes with a ruler at only an arm's-length away.
While these rough guides are conveniences to one entirely un-
accustomed to observing the skies, a very little experience will
soon enable one to estimate distances from star to star by the
eye alone with sufficient accuracy to identify any conspicuous
object in the heavens.
In looking for the brightest stars one may sometimes find him-
self confused by four bright stars that are not, after all, true
stars, but the planets Venus, Jupiter, Saturn, and Mars. Stars
are suns and shine by their own light, as our sun does. Planets
are dark bodies and shine only by light reflected from the sun.
If the planets were as far away as the stars, they would be en-
tirely invisible, and all the differences between them and the
stars which I am about to enumerate are due entirely to the
comparative nearness of the planets.
There are eight planets besides the earth, but the four already
mentioned are the only ones likely to be mistaken for true stars
and thus prove confusing to the ordinary observer. Uranus is
barely visible to the naked eye. Neptune and Pluto can be seen
only with a telescope, and the other (Mercury) on account of
its nearness to the sun is rarely seen at all by the ordinary ob-
server, though when it is visible it appears as a rather bright star.
The first two, Venus and Jupiter, are at certain times brighter
than the brightest stars. Venus sometimes shines so that it casts
a shadow and sometimes can be seen, like the moon, in daylight.
Saturn is usually as bright as a first-magnitude star, and Mars
varies so that it sometimes equals Saturn in brilliancy and some-
times is not so bright. They all move about in the heavens with
seeming irregularity, and when they are in the region of any
bright star may easily be mistaken for it by an untrained ol>
server. A little careful observation, however, will show that they
16 The Friendly Stars
are not as the other stars. They are not fixed in their places, and
a few nights of watching will make this apparent. They do not
twinkle as the stars do, but shine with a steadier light. They are
not mere points of light, as the stars are. Telescopes show them
as rotund solid bodies, though small in comparison with the
other two bodies of which we can see the outlines: the sun and
the moon. A very little watching will make one familiar with
their appearance so that he can always tell Venus and Jupiter
at a glance and usually Saturn and Mars.
Their positions in the heavens are hard to describe definitely
because the planets are constantly changing. They do, however,
keep within a certain limited path, which is within a few de-
grees of the path that the moon follows as it threads its way
among the stars each month, and at some time during the month
it passes near each planet. This is sufficient to indicate that the
planets are never found very far south or very far north.
Venus has still the further limitation of never being more
than about forty-eight degrees away from the sun. When it is in
the evening sky it sets never much more than three hours after
the sun, and when it is seen in the morning it rises never more
than about three hours earlier than the sun. The other planets
within their limited path already described rise and set at various
times within twelve hours of the rising and setting of the sun.
The planets have each a distinctive color, which will assist
somewhat in identifying them. Venus is white; Jupiter is a little
tinged with yellow, Saturn is decidedly yellow, and Mars is
fiery red.
There are many interesting things to observe about the plan-
ets, which are a study in themselves. This brief outline of their
appearance and locations in the sky will be sufficient to prevent
one from confusing them with the stars, which are the special
objects of our quest at present; and with the North Star and the
Dipper wdl in mind, we are now ready to be introduced to the
brightest of them.
Ill
Capella
is a charming star that has the distinction of being
situated nearer to the North Star than any other of the
brightest stars. To find it, draw a line forty-five degrees long
from Polaris at a right angle to the line from the pointers to
the pole and running in an opposite direction from the handle
of the Dipper. It is also pointed out by a line starting at the
star that marks the bottom of the Dipper on the handle side
and running thence about half-way between the two pointers,
for a distance of about fifty degrees, or to the first bright star,
which is Capella. If these directions are even approximately
followed Capella can be discovered, for there is no other star in
its neighborhood that in any way compares with it in brightness.
Capella is one of the most brilliant stars in the heavens. Ca-
pella, Vega and Arcturus are the brightest stars in the northern
hemisphere of the skies. Sirius, as we know, always shines with
greater brilliancy than any other star; but Sirius lies south of
the equator and does not belong among the stars of the northern
hemisphere, although in our latitude it, fortunately, can be seen.
Being so far north, Capella is above the horizon more than
twenty hours out of each twenty-four, so that it can be seen at
some time in the night every month in the year, and one comes
to be on most familiar and friendly terms with its bright face.
Its first appearance in the skies of the early evening is in August,
when it rises about ten o'clock during the first half of the month;
and it remains a constant ornament of the nights until the latter
part of the following June. July is the only month in which Ca-
pella does not show its face at some time before midnight; and
even in July, if one watches closely late in the month, he can
have glimpses of the star following the evening sun at no great
17
18 The Friendly Stars
distance and almost lost in the sunset glow. In October it rises
just as the sun is setting.
Capella rises almost exactly in the northeast and swings in a
fine long circle over the heavens during its twenty-hour journey
to the northwest, where it sets for a brief time, and then rises
again in about four hours.
When you watch the birds congregating in noisy flocks in
the morning for the fall migration, and in the afternoon look
for the first fringed gentians, look for Capella in the northeast-
ern sly in the evening. When the trees are bare and the berries
are wrapped in ice and snow, so that the winter birds greedily
gather in what bounty you throw to them, you will find Capella
shining almost directly overhead early in the evening. During
the spring months, when the air is full of the stir of the awaken-
ing earth, and other stars are demanding our attention to their
return in the east after long absences, Capella is hurrying on
towards the northwest, no longer charming us with its novelty,
but still as bright and fair as ever and ready to fill its place in
the brilliant gathering of the stars of spring.
Capella is yellow in color like our sun and has about the same
surface temperature. Its spectrum is very similar to that of the
sun. The similarity in temperature only means that it has about
the same surface brightness. Capella, however, is a giant star and
our sun is a dwarf, Capella radiating more than 100 times more
light than the sun. Its distance is so great that its light requires
about 46 years to reach us in its journey through space, though
travelling, as light does, with a swiftness of 186,000 miles a sec-
ond At the distance of the nearest star, our beautiful big sun
would shine as a star no brighter than Polaris. But Capella is
ten times farther away than the nearest fixed star, and still shines
as one of the brightest of the bright stars. If Capella were in-
habited, our sun would appear to its people as one of the faintest
stars that we can see with ease. But it is not inhabited, for it is
a very IKK, rarefied and expanded body, as much as forty times
rarer than our sun, and like the other bright stars, no place for
the existence of life as we know it.
It has been discovered in recent years that Capella is not alone
as it makes its journey through the black void. Like so many
other stars, it is what is known a$ a binary system, or a double
star, and has a companion which lies so near it that they circle
Capella 19
around each other in a little more than a hundred days, or less
than one-third of the time that it takes the earth to go around
the sun.
Capella and its companion have never been seen separately even
with the assistance of the strongest telescope. But the wizard
spectroscope has penetrated their family secret and by its means
astronomers have learned that they are two immense, fiery bodies
of nearly the same size and perhaps a hundred times more vo-
luminous than the sun, whirling with incredible speed about
each other. The diameter of the orbit over which the two stars
spin is so large that we could string more than a hundred suns
along it and still have room left for a few more shining beads
of the same sort.
Since it has been known that Capella is a double star it has
been suspected through at least one telescope of being oval in-
stead of round, showing that the two stars have been caught at
a place in their orbit where they appeared side by side to our
view.
These are interesting facts that science, has to tell us about
Capella; but the star that fixes itself in our regard is the fair,
golden, bright Capella that decks the sky in its season. We fol-
low it in its course visible to us across the heavens, we joy in its
beauty and find its gentle light no less gentle on account of
its being the composite of the great orbs we know it is.
Capella is at present receding from us at the rate of about
twenty-three miles a second, or more than a million miles a day.
At first thought this rather makes us fear that we are in danger
of losing this beautiful star from view. But it will be many
thousands of years before even under such speeding away there
will be any appreciable change in its brightness.
The constellation of which Gapella forms a part is called
Auriga. It is a five-sided figure somewhat in the shape of a shield.
It can be easily recognized as soon as Capella is located. It will
be described among the constellations later on.
IV
Arcturus
"P ARJLY in the evening in March there may be seen rising a
little north of east, another bright star that is among the
choicest of the heavenly bodies. This is Arcturus. To find it be-
gin at the end of the handle of the Big Dipper and, following
the curve of the handle, extend a line about thirty degrees, or
until you come to the first brilliantly shining star. There is no
other very bright star in this region; so the line cannot point
you to any other than Arcturus, the self-same star whose bright
beams flowed down more than twenty-six hundred years ago
upon the patient Job and is named by him along with other
wonders of the divine creation.
When one has learned to know the ways of Arcturus and cares
to greet him as he first comes to take his place among the eve-
ning stars in the spring, one begins about ten o'clock in the eve-
ning in February to watch the handle of the Dipper, so clearly,
to the expectant observer, pointing to something important just
below the horizon and then slowly rising until it has pulled into
view the steady shining face of Arcturus. A less attentive ob-
server is more likely to notice the star in March and April, when
die Dipper is almost directly overhead and is turned as neatly
upside down as if it were on the pantry shelf. Its handle, though,
still points to Arcturus, now climbing the eastern skies com-
posedly but rapidly, and making way for the other bright stars
of the spring that will bring on the scene a stellar setting of
their own.
Arcturus rises on the first of March about eight o'clock in the
evening, and during this month, when the horse-chestnut buds
are swelling and the elm-trees are putting forth their first brown
blossoms, and the hawks and owls and crows are prospecting for
nesting sites among the high trees, Arcturus, as if impelled by
20
A returns 21
the onrush of spring, is returning four minutes earlier each eve-
ning until at the beginning of April the star rises just as the
sun sets.
This is really the month of its greatest glory. It shines all
through the evening in the eastern heavens, bright even when
the moon is full, and, fitting in with all the other aspects of
nature, gives a splendid close to the splendid days of late April.
What more gracious day's progress in beauty could there be
than to travel with the eye from the cheerful hepaticas dotting
the soft ground among the trees to the round, white, silent blos-
soms of the dogwood fringing the late April woods and thence,
when evening falls, to the bright yet gentle light of Arcturus
in the sky, announcing the end of the purple twilight.
By the middle of June, Arcturus may be found during the
early evening almost overhead, and it remains in this region
during July. After this, one sees plainly that Arcturus is travel-
ling towards the northwest, sinking lower and lower each month
until, near the last of November, the pointing handle of the
Dipper (the Dipper being then right-side up and below the
pole) shows us that it has gone, almost at the same moment
with the sun, below the northwestern horizon. It is in the eve-
ning skies no more until the next spring. If one wants to see
Arcturus in December or January, he must look for it in the east
between midnight and dawn. It shines for us at some time be-
tween sunset and midnight almost ten months in the year. It
requires about fourteen and a half hours to complete its jour-
ney from rising to setting each day.
Arcturus and Capella are so nearly equal in brightness that
astronomers have differed as to which outranks the other. To
my own eye Arcturus outshines Capella, and on asking various
inexperienced persons for off-hand opinions as to the relative
brightness of the two stars, I have invariably had an answer in
favor of Arcturus. The best authorities now agree with this
impression.
Compare Arcturus with Capella and you will see that the col-
ors do not precisely match. Arcturus, as one can plainly see, is a
little more tinged with red. This means that it is cooler and the
surface not quite so bright as that of Capella or the sun.
These red giant stars are in a very interesting stage of their
astronomical development. They are stars that, having exhausted
22 The Friendly Stars
the primary stellar fuel, hydrogen, are now relying upon second,
ary sources in an effort to escape extinction. Their centers are
much hotter than the sun and this extra heat has caused the
stars to expand until they are bloated in comparison with the
sun.
The total brightness of Arcturus is almost a hundred times
that of our sun. Hence, since the source of fuel is very limited,
this star and other similar red giants are expending their energy
at an enormous rate, which they cannot keep up for long. After
a few thousand years these stars may explode, the remaining frag-
ments condensing to form white dwarfs, like the companion of
Sinus.
Light takes about 37 years to reach us from Arcturus.
These facts are, perhaps, not what we most want to have in
mind when we gaze into the face of Arcturus with its dear,
steady light, but they must have their part in the sum of its
general characteristics and some influence in determining our
feeling towards the star.
Arcturus has the distinction of having the most rapid motion
of any of the brightest stars and it is among the swiftest mov-
ing of all the stars visible to the naked eye. Enormous body as
it is, we know that it is bowling along through space at the rate
of between two and three hundred miles a second. It has been
doing this for untold centuries, and yet it does not change its
position to our view a distance of more than one-tenth of the
apparent diameter of the moon in a century. This is, however,
an enormous change for a "fixed" star and will, in the course of
ages, make an important difference in the position of Arcturus
among the other stars.
It is pleasant to know that this bright star is approaching us,
though it decreases the distance between itself and us only at
the rate of two and one-half miles a second, a very loitering gait
in comparison with the speed of stars in general. The most that
it can mean to us is that Arcturus will not grow less bright in
oiir skies because of increasing distance; for at this rate of ap-
proacfa untold centuries must pass before the distance between
us and the star is lessened so as to make any appreciable increase
ia its brightness. Such increase, indeed, possibly never will be
made. For, as previously noted, Arcturus is growing old and
Arcturus 23
may well alter its appearance before changing distances have
much influence on its apparent brightness.
Arcturus lies in the constellation Bootes and is, of course, its
brightest star. The name signifies "Watcher of the Bear," a title
derived from its proximity to Ursa Major.
V
Spica
A NOTHER bright star, and one that comes into view not long
after Arcturus, is Spica. It is not so bright as Arcturus, but is
still a conspicuously brilliant star. Among the twenty-one brightest
it is the fifteenth in order of brilliancy. To find Spica easily
extend the line from the end of the handle of the Dipper
through Arcturus and about thirty degrees beyond, still fol-
lowing the curve. It is about as far from Arcturus as Arcturus
is from the handle of the Dipper. A straight line beginning at
the pointer nearest the pole, running through the star at the
bottom of the Dipper on the handle side, and extended about
sixty-five degrees farther on, will also point out Spica.
Spica rises a very little south of the exact eastern point on
the horizon and becomes visible about an hour later than Arc-
turus. It is the only very bright star in the southeastern part of
the heavens during the early spring months, and one cannot
easily fail to identify it even without the specific directions for
finding it that are here given. It first attracts one's attention in
the early evening about the middle of March, at which time it
rises about eight o'clock and by nine has cleared its face of the
haziness of the lower atmosphere and is shining with a clear
irfute light.
Spica does not make so long a sweep across the heavens as
Capella and Arcturus do. It is one of the stars that lie a little
south of the celestial equator, and at the highest point in its
journey across the sky Spica is still to the south of us and almost
one4ialf of the way up from the horizon to the point exactly
orafeead, which we call the zenith. It takes five hours and a
half to reach its highest point and as many more to travel to
the southwestern horizon, where it sets eleven hours after it has
risen.
24
Spica 25
Spica rises just after the sun sets in the early part of April;
and during April and May it is at its best in the eastern evening
sky. Its position, however, always comparatively low in the sky
to our view, makes it easy to observe at all times when it is
visible. During the short evenings in June Spica lies towards the
southwest, where in August it sets about ten o'clock, in Septem-
ber at about eight o'clock, and in October about the same time
that the sun goes down. It can be seen between sunset and mid-
night in some part of the sky from the middle of February to
the early part of October. In November, December, and Jan-
uary it rises between midnight and dawn, so that October is
the only month during which it is most of the time invisible.
This is because it lies in the constellation Virgo, or the Virgin,
through which the sun is passing in October, and the star is
lost in the rays of the sun. Spica lies almost on the ecliptic,
which is the line that marks the annual path of the sun through
the heavens.
Spica's color (blue white) shows that its surface temperature
is higher and surface brightness greater than that of either Ca-
pella or Arcturus. It is, therefore, a much smaller object. It is
about six hundred times brighter than our sun and so far away
that it takes light about two hundred and sixty years to reach
us. Spica is receding from the earth at a snail's pace, compared
with most stars about one mile per second.
The name Spica means an ear of wheat, and the star marks
the spot in the constellation Virgo where the Virgin holds in
her hand a spear of wheat.
VI
Vega
ABOUT three hours after Arcturus has risen there will come
peeping over the northeastern horizon a brilliant, bluish star
ifhkh twinkles so gayly and commands such instant admiration
that its entrance into view has almost a dramatic effect. This is
Vega, the third of the trio of bright stars that give a May-dance
around the pole. Her companions, bright Capella and steady-
shining Arcturus, are already gliding smoothly over the shining
surface of the sky when she, clearing the tree-tops almost with a
bound, lightly springs into view and the vernal festival is on.
The point on the horizon at which Vega makes her appear-
ance is about fifty degrees from the pole. She lacks about seven
degrees of being as far north as Capella, and is nearly twenty
degrees farther north than Arcturus.
To find Vega, draw a line from the star at the junction of the
bow! and the handle of the Dipper to Polaris. Then draw a line
at right-angles to this nearly forty degrees in length and on the
same side of the Dipper from which the handle projects, and it
will point out the brilliant, beautiful Vega. The star is the only
conspicuous one in the region described, and no other star can
be mistaken for it.
Vega is on the opposite side of the pole from Capella, but the
two stars are usually seen in the sky at the same time. In the
spring, when Vega decks the eastern heavens, Capella glows in
the northwest In the autumn, when Capella comes sparkling
over the dark purple sky in the northeast, Vega may be seen
Sying with its attendant stars down towards the northwest. Each
one is hidden below the horizon for the few hours that the other
holds the center of the celestial stage and is at its highest point
in its nightly course across the jewelled dome of the sky.
Vega as the starting-point, you will find that Arcturus
26
Vega 27
is about one-third of the way between Vega and Capella, though
a little farther away from the pole. The part that Arcturus plays
in the gay spring festivities is very conspicuous, and at that time
the three stars are closely associated in their splendid, twinkling
circuit around the pole which it may please our fancy to watch
during the first soft nights of spring. In the autumn, when Vega
and Capella have changed places in the evening skies, Arcturus
is below the horizon and cannot be seen.
If one is in any doubt about the identity of Vega, it can al-
ways be recognized at a glance by the fact that four dainty stars
arranged in an oblique parallelogram follow it.
The position shown in the drawing is the one they always
hold relative to Vega. When we see her in the east as she bright-
VEGA (IN LYRA) AS SHE APPEARS IN THE EAST
ens the evening view in the spring and early summer the four
stars are to the east of, or below, her; in the late autumn and
winter, when the constellation is in the western sky, the posi-
tion of the stars, as it appears to us, is partly reversed, and,
with Vega leading them towards the northwestern horizon, they
appear as shown in the illustration,
Vega, like Capella, can be seen in our latitude at some time
during the night every night in the year. One can see it even
between sunset and midnight every night in the year. But to do
this it will be necessary to keep a sharp lookout low in the north-
west very early in the evenings in February and to turn just as
sharp eyes towards the northeast between eleven and twelve
28
The Friendly Stars
S>
+40
VEGA AND HER ATTENDANT STARS IN THE NORTHWEST
o'clock in the early part of March. As April progresses the star
more and more asserts its supremacy in the northeastern heavens.
During the latter part of this month and all of May it is singu-
larly beautiful as it passes almost airily between us and the rich
dark background so full of color characteristic of the spring-
time sky.
Vega is the chief star in the constellation called Lyra, the Lyre
-once fancied to be the magic lyre which in Orpheus' hands gave
forth music that tamed wild beasts and chained the rivers in
their courses. It is easy to get some sense of the fancy that gave
the constellation its name as we watch it during the lovely spring
evenings floating lightly in the sky, the parallel lines connecting
its principal stars vaguely suggestive, to the willing mind, of
some quaint stringed instrument that under a magic touch might
sead out heavenly music through the resonant air.
Early in May the star rises at about the same hour that the
sun sets, and all summer long it is the gayest and perhaps the
most instantly attractive star in the evening skies. It is the star
so often noticed and commented on as shining with great bril-
liancy directly overhead between nine and ten o'clock during
the hot summer evenings of July and August. When autumn
comes Vega has passed the highest point in its journey across
the heavens and may be seen travelling towards the northwest.
Here it shines splendidly during the early evening, setting in De-
cember somewhere near eleven o'clock and in January about
Vega 29
nine. It is above the horizon eighteen hours out of each twenty-
four and rises six hours after it has set.
Vega is one of the three most brilliant stars in the skies of the
northern hemisphere; Capella and Arcturus closely match its
brightness. Only three stars in the entire heavens, north or south,
are appreciably brighter. These are Sirius, Canopus, and Alpha
Gentauri, all stars of the southern hemisphere. Sirius, as we
know, can be seen in our latitude, but it lies south of the celes-
tial equator, and is, therefore, called a southern star. The other
two lie so far south that they do not ordinarily come within our
view, although Canopus barely creeps above the south horizon
for southern locations.
Vega is one of the very bright suns of the universe and is 50
times brighter than our sun. Its distance is such that it requires
about twenty-seven years for light to travel from it to us; thus
Vega is somewhat nearer to us than Capella and Arcturus. The
surface temperature of Vega is less than that of Spica but con-
siderably greater than that of Capella or Arcturus.
One of the most interesting things about Vega is that it seems
to mark, or nearly mark, the point in space toward which our
sun with all his planets is travelling. Vega, of course, has noth-
ing whatever to do with this motion. It is coming nearer all the
time, too. Ten miles a second is about the rate at which it is
approaching us; but, as we have already seen, it will take many
centuries for even such almost incredible speed as that to make
any appreciable difference to us in the brightness of a star.
On some old maps Lyra appears as a Vulture. Vega is said
to mean "the swooping vulture."
VII
Deneb
A LITTLE more than an hour after Vega has risen, a bright
twinkling star will appear on the northeastern horizon at
a point about forty-five degrees from the Pole Star. This is De-
neb, nineteenth in the list of the twenty-one brightest stars, but
a very interesting and beautiful star. It lies in one of the densest
parts of the Milky Way and is conspicuously brilliant in contrast
with the hazy light of the myriads of small stars that go to make
up this mysterious belt of shining bodies.
Deneb is about six degrees farther north than Vega and only
about one degree farther south than Capella, which, as we have
seen, is the northernmost of all the bright stars. To the ordinary
view Deneb and Capella seem to rise at about the same spot on
the horizon, and they describe very much the same long, oblique
curve across the heavens as they pass from rising to setting. Ca-
pella being a little farther north, is above the horizon perhaps
half an hour longer than Deneb; but they each take approxi-
mately ten hours to come to the highest point in their path
across the sky, and, consequently, in a favorable atmosphere,
can be seen for about twenty hours each day, except when they
are obscured by the sunlight. The highest point a star ever
reaches in its daily course over the heavens is marked by what
astronomers call its meridian, and when it is at this point it is
said to be "on the meridian."
A line drawn from Polaris to Deneb and thence on to Vega
forms a right-angled triangle of which Deneb lies in the right
Deaeb forms a part of a figure called the Northern Cross,
wfeidi extends over the Milky Way something more than twenty
Degrees. The figure serves to identify the star, but it is a rather
ill-formed cross and not much more like a true one than the
Deneb
31
far-famed Southern Cross, which is so impressively described by
travellers in southern latitudes and is so disappointing, on first
sight, to the observer who expects accurate rather than sugges-
tive outlines in the constellations.
Deneb is the star at the head of the upright of the cross. In
the spring, when it rises in the northeast, the cross is almost up-
side down, and Deneb comes up last. "When the cross is setting
4-80
+70
-{-60
+50
+40
18*
TRIANGLE FORMED BY POLARIS, DENEB, AND VEGA
^2 The Friendly Stars
in the northwest, its position is partly reversed, so that it seems
more nearly upright, and Deneb disappears last.
While this figure is commonly spoken of as the Northern
Cross, it is really only a part of a larger constellation known as
'Deneb
119*
+40
-1-30
20*
THE NORTHERN CROSS, PART OF CYGNUS, THE SWAN
Gygnus, or the Swan, and this is the name used by astronomers
in referring to the constellation in which Deneb is found. It
was named by the ancient astronomers, and was thought by them
to suggest the figure of a flying swan, the out-stretched wings be-
ing represented by the stars which form the arms of the cross.
The bead is marked by the star at the base of the cross, and in
die tail is Deneb. The name "Deneb" means "the tail/' and the
star gets its name from its position in the constellation. Deneb
Deneb 33
has sometimes been called Arided, an Arabic word which means
"the hindmost," though the name is rarely used.
The swan represented by this constellation was supposed to
be the one whose form Jupiter assumed when he visited Leda
incognito; and having served the purpose of the god, what more
natural than that its empty but sacred form should be placed
forever in the heavens?
Although eighteen other stars (fourteen in our latitude) seem
to us brighter, Deneb exceeds most of them in size and certainly
in intrinsic brilliancy. Actually, Deneb is about sixty thousand
times brighter than our sun. Also it is very distant, so far away
that light takes about 1400 years to reach us. This means that
Deneb is so many millions of millions of miles away that if its
distance were expressed in figures they would be more than the
mind can grasp.
Deneb is white in color, with a surface temperature similar
to that of Vega. However, it is indeed a much larger star than
Vega, of a class sometimes called "supergiant."
Deneb, like Capella and Vega, can be seen at some time be-
tween sunset and midnight every night in the year. It is closely
associated with Vega as an ornament of the sky, because they
adorn the same portion of the heavens at the same season. Fol-
lowing almost in the wake of so dazzling a star as Vega, Deneb
may at first excite less interest and admiration than is its due;
but a closer acquaintance with its sparkling face will show that
its beauty is no more eclipsed by Vega than the low nodding
anemones are eclipsed by the splendor of the magnolias. They
each have their own individual charm.
Deneb arrives at the spring gathering in the east an hour later
than Vega, but, being farther north, it pursues a longer course,
and, coming leisurely to the western sky, it lingers in our view
each day for three hours after Vega has gone. Deneb is particu-
larly attractive in this part of its path during the early evening
in January and February. It is then rather low in the northwest,
and with Vega gone and no other bright star very near, it has
a more commanding charm. In the heavier atmosphere, which
induces a more rapid twinkling, the star seems to take on an
accession of gayety and goes fairly dancing down behind the
horizon, where it finishes its circle and appears again in the
northeast about four hours later.
54 The Friendly Stars
Deneb rises just after the sun sets about the middle of Ma
and sets about an hour after sun-down during the early part o
March.
Inasmuch as Deneb is so far distant, it is interesting to kno\
that in the same constellation (Gygnus) and not many degree
east of Deneb, or below it as it rises, lies a star famous as beinj
the first whose distance from us was measured. This star, whid
bears the unprepossessing name of 61 Cygni, is about clever
light years away. Currently (1962) it stands eleventh in the lis
of nearer stars, not counting the sun, 61 Cygni, which is it
catalog designation, is not much more than visible to the nakec
eye, though a keen eye can see it on a dear night. Its position i
marked on the diagram of the cross on page 32.
The star at the foot of the cross, or in the beak of the swan
as one chooses to figure the constellation, is Albireo, a fin<
double star. It is easily resolved into two stars by a small tele
scope and is notable on account of the strong contrast in coloi
between the two stars composing it. One is a deep blue, and
the other a bright orange.
VIII
Altair
LINE about eighty degrees in length drawn from the pole
towards the south and running about half-way between
Deneb and Vega will point to the brilliant white star Altair. It
is almost twenty degrees directly south from Albireo, mentioned
in the last chapter as marking the base of the Northern Cross. It
lies just at the edge of the Milky Way; and, for any one who has
learned the position of Deneb, it will be easy to find Altair by
running the eye down the Milky Way from Deneb along the up-
right of the Cross to Albireo at the foot of it, and thence on
twenty degrees, or to the first very bright star, which will be no
other than Altair.
The constellation in which Altair is situated is known as
Aquila, or the eagle; and Altair is the middle one of three fairly
bright stars placed with reference to each other in a straight line.
Indeed the name Altair means "the Flying Eagle."
The lines between Altair and Deneb and Vega form an acute-
angled triangle with the short side towards the north and Altair
at the apex at the south.
Altair rises about eight degrees north of the exact eastern point
on the horizon and about ten degrees south of the spot where
Arcturus first appears. It is the only very bright star in this region
of the sky, and there will be no trouble in identifying it. One of
the interesting figures that serve to mark the locality is a small
diamond-shaped group of four stars lying about ten degrees
northeast of Altair.
This group is the constellation Delphinus, or the Dolphin,
more popularly known as "Job's Coffin." Why the figure should
suggest a coffin rather than a dolphin, it is not easy to see. It
hardly resembles either object.
Among the stars of the northern hemisphere, Altair is the first
35
The Friendly Stars
20* 19"
ALTAIR AND ITS Two COMPANIONS IN AQUILA
bright star to daim our attention in the east after Vega and
Deneb have made their brilliant close to the gathering of the
stars of spring, Capella is within two hours of setting in the north-
west, Arcturus is nearing the highest point in his course across
the heavens, Spica has reached the meridian, and Vega is about
half-way up to the zenith, when, on the first of June, between
half-past eight and nine o'clock in the evening, Altair makes its
gracious entrance into the starry company. With one exception,
it is the most attractive of the stars that rise during the early
evening in summer. By the middle of the first summer month
there is a lull in the noisy rush of the on-coming season. The
dazzling blossoms of the fruit trees are scattered and almost for-
gotten, while the tiny green outlines of the fruit are quietly
swelling towards their perfect form. The leaves on the forest
trees have assumed their proper shape and are gradually expand-
ii^j to full size. The old-fashioned annual roses are in their
Altair
.40*
+10
DENEB, ALTAIR, AND VEGA
fullest glory. The blue jays have become stealthy and quiet; and
most of the birds, while still in full song, have given over the
frolicsome hilarity of the spring for the serious work of the nest-
ing-tune.
Then there comes a soft June evening, with its lovely twilight
that begins with the last song of the wood-thrush and ends with
)S The Friendly Stars
THE DOLPHIN (DELPHINUS), OR JOB'S COFFIN
the first strenuous admonitions of the whippoorwill; and, almos
as if it were an impulse of nature, one walks to the eastern enc
of the porch and looks for Altair.
It is sure to be there smiling at one just over the tree-tops, wit!
a bright companion on either side, the three gently advancing ir
a straight line as if they were walking the Milky Way hand in
hand and three abreast.
From this time on until the first half of December is past,
Altair is in view early in the evening. Always an attractive star,
it is never more charming than in September and October. It
ti*en lies due south of us and at its highest point, which is about
two-thirds of the way up from the horizon to the zenith. This
favorable position, added to the peculiar clearness of the
autumn sky, brings out all the soft beauty of the star.
One seldom sees Altair during the first four months of the
year. Along 10 the very first days of January a prompt lookout
and a dear sky will yield a glimpse of it between sunset and
seven o'clock; but it is soon lost in the glow of the rapidly
lengthening days. In February, March, and April the very early
Altair 39
riser and the belated watcher after midnight may see the star rise,
and in May, as the month progresses, it becomes a more and
more familiar figure in the east.
There is nothing spectacular in the advent of Altair, and one
does not watch for it with the same eagerness that he feels when
Arcturus and Vega are nearly due. It comes gently into sight,
and almost before one realizes it the star has become a part of
the evening view. Arcturus and Vega suggest the bustling coming
of spring. Altair reminds us of the quiet approach of summer.
It requires about thirteen hours for Altair to pass from its
rising to its setting; six hours and a half to reach the meridian,
and six and a half more to finish its diurnal course. Remaining
as low in the sky as it does, one can see it and yet remain in a
comfortable posture during its entire passage across the heavens.
This adds greatly to its charm; for any star is, in itself, most
beautiful when in the highest and clearest part of the sky. Only
the difficulty of seeing it there may detract from our pleasure in
it. One cannot come into any great fondness for a star that he
sees only by snatches. The stars that we love best are the ones
into whose faces we can look for an hour at a time, if our fancy
so leads us. It is truly star-gazing that brings us into any great
delight in a star.
Altair is white or yellowish white. Its surface temperature is
somewhat less than that of Vega but still higher than that of
Capella. Its true luminosity is about eleven times that of the sun.
Light takes about seventeen years to reach us. In this respect,
Altair is not one of the far distant suns, but is comparatively
near us. The star itself is approaching us at the rate of about
sixteen miles a second or more than 200 millions of miles a year.
Yet even with this marvelous speeding toward us, and in spite
of its comparative nearness, considerably more than 100 thous-
and years would be required for Altair to reach the place in the
universe that we now occupy.
IX
Antares
A BOUT ten o'clock in the evening of the longest day in June
"^is perhaps, the most favorable time to look for Antares a
beautiful star in a beautiful constellation. It then lies due south
and at the highest point in its diurnal path across the heavens,
which never takes it higher than a little more than one-fourth of
the way from the horizon to the zenith. A line about one hundred
and sixteen degrees long drawn directly south from Polaris and
passing just half-way between Arcturus and Vega will point it
out, lying in the heart of the constellation Scorpius, which is
flung out over the southern sky in a fine sweep that wins admira-
tion from the most casual observer.
Antares is also indicated by a line drawn at right angles to
the line connecting Altair and its two companions and extended
about sixty degrees, or to the first brilliant red star, Antares,
the only one of its kind in this most interesting region of the
skies. An almost equal-sided triangle about fifty degrees long on
each side is formed by the lines connecting Antares, Vega, and
Arcturus, which is a still further guide to the location of the
star.
Antares is one of the southern stars that lie south of the celes-
tial equator, no matter whether they are visible to us or not. It
is, with one exception, farther south than any other of the very
bright stars (stars of the first magnitude) that can be seen in
our latitude. It rises in the southeast and has so short a course
ower which to pass, in our view, that it reaches the half-way
point, or the meridian, in about four hours and a quarter.
Antares comes into view two hours and a half later than Vega,
aua hour and a half later than Deneb, and nearly an hour earlier
than Altair. But it is so much farther south than Altair that it
seems more aloof from us and it scarcely emerges from the hazy
40
An tares
41
lower atmosphere until Altair is shining gayly and has already
become one of the important figures in the eastern summer sky.
While the latter pan of June and all of July are perhaps the
best times to see Antares at its brightest, it is an interesting star
to observe much earlier in the season. If one has an unobstructed
view of the southeastern sky down almost to the horizon, he will
42 The friendly Stars
note the appearance of Antares as early as the middle of May
between nine and ten o'clock in the evening. Before one has
really seen the star, he becomes conscious of a ruddy glow low in
the southeast that at once fastens the attention. It is the face of
Antares, whose red light shining through the heavy atmosphere
is so diffused that it gives a rosy effect to the sky for a consider-
able distance around the star, like a miniature presentment of
the sun as it rises on a hazy morning. This is all the more notice-
able because it is so in contrast with the usual colors of early
May. They are all of the more delicate and colder sort, from the
pinkish-lavender and white of the young leaves that shimmer
over the landscape to the pinkish-purple of the sky and the
dazzling white and blue of Deneb and Vega and a few other
stars that belong particularly to this season,
The fact that Antares, when it is visible at all, is always so
low in the sky and so clearly before our eyes when they are
turned towards the south, makes it a constantly conspicuous
figure in the heavens during its entire stay. It is fortunate that
this is so, for the stay of Antares is short. It is visible in the eve-
ning between sunset and midnight for only six months, and
during only one of these months (June) is it visible all night.
In November and December and most of January it is above the
horizon only in the daytime, and in February, March, and most
of April it is not high enough to be dearly visible until after
midnight. In the early part of June it rises just as the sun sets.
I am not sure that the color of Antares is any reason why it
should be associated with the blooming of red flowers; but I
find in my journal of out-door things that I have unconsciously
made the association. One entry, on June 30th, says: "Antares
is stoning splendidly to-night and rivals in color the wild red
lilies that were blooming to-day in the coppice down beyond the
spring." Another entry, on August 5th, says: "We found the first
cardinal-flowers to-day," and a little farther on, "Antares is al-
laost as red as a cardinal-flower to-night." It is certain that the
wood lilies bloom when the star is at the culmination of its
summer glory, and the cardinal-flower sends up its flaming
stalks when the star is speeding after the sun and sets about
midnight. Its bright red color, too, is accentuated when Antares
is near the setting-point in the southwest, just as when it was
rising in the southeast.
An tares 43
Although Antares is almost strictly a summer star, it is a very
significant object in the southwestern heavens during September
and October and is often commented on at that time by persons
who have not noticed it earlier in the season. The dark back-
ground of the autumn sky throws the flaming face of the star
into relief, and its redness is still further intensified by the white
sweep of the Milky Way, which is then very bright and which
lies within a few degrees of Antares.
The constellation of which Antares forms a part (Scorpius)
represents the scorpion that stung Orion, and it is the "hissing
snake" from which Spenser represents Orion as "flying fast." The
two constellations are so placed in the skies that Orion dips below
the western horizon just as Scorpius rises in the east, and the
mighty hunter does not return until the Scorpion is gone. They
can never be seen at the same time.
The name Antares signifies "Rival of Mars." And indeed the
red color of these two objects is most striking. It is particularly
so when, every couple of years, Mars in its course through the
ecliptic chances to be in Scorpius. For then the star and the
planet stand out in splendid contrast.
Antares belongs to that class of stars known as the red giants.
It is even more distended and swollen than Arcturus. Its redness
indicates that the star is cooler, with a less luminous surface than
Arcturus has. Actually it is about five thousand times brighter
than our sun and very much larger. If Antares were set in the
position of our sun, the earth would still be somewhat below
the surface. Light takes about 400 years to reach us from this
star.
Red giant stars, like Antares, are believed to be objects in their
old age. Most stars derive their energy from the fusion of hydro-
gen atoms into heavier substances like helium. But when a
star has exhausted most of its hydrogen, the internal core tends
to contract, grow hotter, so that the star can for a very short
time live on other energy sources. The outer layers swell up
and the star becomes very luminous. But after some thousands
of years of this spendthrift activity, these sources, too, become
exhausted. The star has nothing left to do but collapse on the
inside and explode on the outside, becoming a nova, or new
star. Gravitation will then collect the fragments into a small,
44 The Friendly Stars
feebly shining star of the type known as a white dwarf, like the
companion of Sirius.
Antares is one of a binary system. Its companion is remarkable
for its greenish color, which forms a strong contrast with the
scarlet light of the larger star. The companion can be seen, how-
ever, only with a fairly large telescope, partly because of its
proximity to the primary and also because it is three magnitudes
fainter.
X
Fomalhaut
CTILL lower in the southern sky than Antares and in a coin-
^paratively starless region shines Fomalhaut, the lonely, the
eighteenth star in point of brightness among all the stars in the
heavens and the thirteenth among those that can he seen in our
latitude. It is so completely isolated from other bright stars that
it needs no special line to point it out. But if the line that leads
from the pointers to the Pole Star were extended beyond the
pole and on directly south about one hundred and twenty de-
grees, it would end near Fomalhaut. This will be an easy line to
trace during the months when Fomalhaut is visible, for the point-
ers will then be shifting from a position west of the pole to one
directly under it, and the line will have a free path across the
heavens. The star may be easily recognized without any other
description than that it is at the end of a zigzag line of small
twinkling stars which runs across the southern sky in the autumn
and points unmistakably to Fomalhaut. The small stars repre-
sent the stream of water that Aquarius is pouring from his urn.
The stream runs to the constellation known as the Southern Fish
(Piscis Austrinus) , and Fomalhaut means the mouth of the fish.
There is a calm dignity about this star that lends much interest
to it. It comes gently into view far down in the southeast in
August, but with so little of a flourish that one scarcely notes
its presence until along in early September. Then, when the days
are growing shorter, some evening, just after dark, one sees it, a
conspicuous, impressive object serenely trailing along over the
small arc of its circle in the south with no companion near it,
and, apparently, no need of one to add to its splendor.
On early acquaintance the loneliness of the star, added to the
sombre signs of approaching autumn, sometimes gives one a
touch of melancholy. But its aspect when more familiar soon
45
46
The Friendly Stars
-20*
22 h
FOMALHAUT
comes to suggest only sweetness and serenity, and a lover of
Fomalhaut feels that a sustaining light has gone when, during
the last of December, this beautiful star sinks gently down in
the southwest and disappears from the evening sky not to return
for more than seven months. One loves to recall that Fomalhaut
makes a lonely but majestic sweep high in the heavens of the
southern hemisphere: a sweep somewhat larger than Arcturus
makes in our skies.
Fomalhaut and Capella rise at almost exactly the same minute;
but the path of Fomalhaut across the sky is so short that it has
finished its course and vanished more than two hours and a half
before Capella has reached its half-way point, the meridian.
Rising together as the two stars do, one seeks to continue some
dose association between them; but they have nothing more in
common. In the course each has to run and the joy each has to
give they are as widely divergent as two royal babes born at the
same moment on different sides of the globe.
Fomalhaut is one of the four "royal" stars of astrology. The
othess are Regulus, Antares, and Aldebaran.
Only eight hours are required for Fomalhaut to pass from
rising to setting, and at its highest it is never quite one-fourth of
the way up from horizon to zenith. It is the farthest south of any
very bright star visible in our latitude.
Fomalhaut is distinctly a star of the autumn. When it first
Fomalhaut 4J
appears in August the nights have already begun to grow longer,
the hirds have ceased to sing and are seeking the deeper shadows
of the woods in which to shed their summer suits, and the quiet of
autumn is everywhere stealthily creeping upon us. At the time
of the equinox, in September, the star rises about an hour after
night falls and is on the meridian between ten and eleven o'clock
in the evening. About the middle of October Fomalhaut rises as
the sun sets and shines until two o'clock during the first white
frosty nights. In November and December, when even the most
hardy insects have stopped their shrill notes and the winter still-
ness has fallen upon us, a glance towards the southwest will dis-
cover Fomalhaut, still placid and alone, on its way to adorn the
warmer southern skies, its serenity in no wise disturbed and its
beauty in no wise eclipsed by the more spectacular entrance of
the brilliant winter stars now gathering in the east.
Notwithstanding that to our view Fomalhaut is surpassed in
brightness by seventeen other stars, it actually gives out about
fourteen times as much light as the sun. While not one of our
nearest neighbors among the stars, it is still not so very far away,
for its light reaches us after a journey through space of only 22
years. There are only four other stars among the twenty-one
brightest that are known to be nearer to us.
Fomalhaut has no companion star. It is not only in a more or
less starless region to our view, but its loneliness seems to be
actual.
I have preferred the pronunciation Fo'-mal-o as being more
melodious than Fo-mal-hoot', a pronunciation sometimes rec-
ommended by the authorities.
XI
Aldebaran
HPHE stars thus far described have a particular connection with
the spring, summer, and autumn months. Capella, it is true,
shines throughout the winter; but it can be seen while the eve-
nings are pleasant, and as it is in the most convenient position
for observation in the spring and fall, it belongs, in large part, to
the out-door season. There are, however, six brilliant stars that
are distinctly of the winter. They are not only of the same season,
but in a way they belong together, for they are in constellations
that join each other and spread out in a splendid panorama
across the southern skies, making the most dazzling display of
fixed stars that any part of the heavens affords. These six stars are
Aldebaran, Betelgeuse, Rigel, Pollux, Procyon, and Sirius.
Of these six stars Aldebaran is the first to appear. Along in
September, a very little north of east it shows its fiery face above
the horizon with such unmistakable individuality that it catches
the eye of even the least observing. It appears at a point about
thirty degrees farther south than Capella and rises about two
hours and a half later than that bright star. But it is hardly less
conspicuous, for though its actual brightness is rated nearly a
magnitude lower than Capella's, it glows with a rosy light that
demands recognition and at once pronounces it one of the most
important heavenly bodies.
AWebaran lies at the open end of a bright V-shaped duster of
stars known as the Hyades.
The duster is in the head of the great constellation Taurus, or
the Bull, and the star itself marks the fiery eye of the enraged
b*iH as he lowers his head for a lunge at Orion.
It fa difficult to miss finding Aldebaran if one watches in the
region indicated, during late September or early October, for
the first bright star that rises after Capdla. The locality is still
4*
Aldebaran
49
-4-20
THE HYADES
more distinctly marked if one chances to know the shimmering
light of the Pleiades, which are in the same constellation as
Aldebaran and constitute the one group of stars that is usually
familiar to the youth who celebrate Hallowe'en. Aldebaran
shoots its ruddy face above the horizon just an hour after the
hazy little dipper of the Pleiades has appeared and the star is
then to the east of, and, hence, almost directly under, the Plei-
ades. This following of the Pleiades is what gives Aldebaran its
name, which means "the hindmost," or "the follower/*
Aldebaran shines in the evening skies for about eight months
in the year. It becomes a fixed ornament of the eastern sky about
the last of September, when it rises between nine and ten o'clock.
The ruby Antares has been below the western horizon for nearly
an hour when the still brighter ruby Aldebaran comes into view
in the east. The two stars can never be seen at the same time
and they do not at all resemble each other except in color. Even
in this respect they differ, for Antares is a deeper red than Alde-
baran, though not so bright a star. But as one watches the slow
sulking of red Antares in the southwest, and gives a sigh of regret
when he has entirely disappeared, it seems but a natural associ-
ation that draws one's eye towards the east to watch with eager-
$0 The Friendly Stars
ness for ruddy Aldebaran to give that touch of color which the
sky seems to lack.
In astrology these two stars were known as "royal" stars, and
there is a whimsical suggestion of royalty in them now as the one
slips away from our admiring gaze and we turn to hail the com-
ing of the other. ''The king is dead! Long live the king!"
In his section of the sky Aldebaran reigns throughout all the
lovely autumn evenings, with beautiful Capella in her own
realm to the north of him and Fomalhaut far to the south. His
near associates are in the bright groups that I have called the
winter stars, and they appear in quick succession after him.
From the time Aldebaran first appears until late in December
it may be seen in the eastern heavens in the early evening. It
rises just as the sun sets near the first of December and reaches
the meridian seven hours later. In January and February, Alde-
baran is at its highest point early in the evening and is then a
little more than two-thirds of the way up to the zenith. At the
same hours in April it is conspicuous in the western sky, and by
the end of May it has disappeared. In June it is above the hori-
zon only in the daytime, and in July it can be seen not long
before the sun rises.
Aldebaran is the thirteenth star in order of brightness in the
entire heavens and the ninth among those seen in our latitude.
It is what is known as a standard first-magnitude star. It gives to
us about one 90-billionth as much light as the sun, but at the
same distance from it as we are from the sun we would get from
it about 100 times as much light as we do from the sun. It re-
quires approximately 70 years for the light of Aldebaran to reach
the earth, which means that it is nearly 400 trillions of miles
away. It is increasing this distance at the rate of about 30 miles a
second; but even at this rate it will require more than 10,000
years to add another trillion of miles to its distance.
Aldebaran lies in the path that the moon follows as it crosses
the heavens, and is frequently obscured from our view by the
moon's passing between it and the earth. Such an intrusion of
the moon is called an occultation, and is an interesting phenom-
enon when the subject occulted is either a bright star or a planet
A star, in such a case, disappears behind the moon instantly, be-
cause a star shows no sensible disk. A planet disappears gradually.
Aldebaran 51
Aldebaran has an extremely faint companion star, which can
be seen only with a powerful telescope. Aldebaran also belongs to
the class of old, dying stars a red giant like Antares.
XII
Orion's Bright Stars
"VT EXT to the Great Dipper, Orion is probably the most widely
^ known of all the constellations. It contains more bright stars
than any other single group, and they exact all the more im-
mediate admiration because they are clustered so closely and
symmetrically as to form a set figure of dazzling jewels a verita-
ble "sunburst" of "diamonds in the sky."
To the ancients this figure, as its name indicates, represented
the giant Orion placed in the heavens in heroic attitude facing
Taurus, the mighty bull, who, with fire darting from his eye
(marked by Aldebaran), is about to make an onset with his
splendid long horns. Orion stands with his right arm uplifted
and his great dub in the air ready to strike. Over his left arm
hangs a lion's skin, which he holds up as a sort of shield before
him. With a little play of fancy it is not difficult to see in this
constellation a colossal figure, splendidly poised and full of
action. The accompanying diagram shows the figure as outlined
by the stars.
Orion not only includes an unusual number of bright stars,
but it has the further distinction of being the only constellation
visible in our latitude that contains as many as two stars of the
first magnitude, or highest degree of brilliancy. These two stars
are Betelgeuse and Rigel. Betelgeuse marks the right shoulder
of Orion, and Rigel is in the left foot. In the strictest sense,
Betelgeuse signifies armpit and Rigel the left leg.
The first of these to appear is Betelgeuse. It pushes its red face
up over the horizon about an hour and a half after Aldebaran
has risen, and is only about nine degrees farther south than Alde-
baran. It is of about the same degree of brightness as Altair, but
it has not the same cheerfulness of aspect. On the contrary, there
is a decided suggestion of sombreness in its dull and compara-
tively untwinkling face.
52
Orion's Bright Stars
+20
ORION
The color of Betdgeuse is deep red. It is, therefore, a con-
spicuous member of the group of red giants like Antares and
nearby Aldebaran, stars nearing extinction. This period of stellar
evolution is probably responsible for the fact that the star fluctu-
54 The Friendly Stars
ates in brightness, for Betelgeuse is one of the class known as
irregular variable stars. In other words, it passes irregularly bom
its brightest to its dullest stage of lucidity. Occasionally it attains
the brilliancy of Vega or Capella; sometimes it is no brighter
than Spica or Antares. But it always remains bright enough to be
a first-magnitude star.
About fifteen or twenty minutes after Betelgeuse has appeared
Rigel comes twinkling into view. It is the brightest star in Orion
and lies about sixteen degrees south of Betelgeuse. The celestial
equator runs just about half-way between the two stars; so that
Betelgeuse belongs to the northern hemisphere and Rigel to the
southern. With Aldebaran, these two stars form a triangle, the
sides being from sixteen to twenty degrees in length. Rigel is
exactly south of Capella; hence, a line drawn from Polaris
through Capella and extended a little more than fifty degrees
will end at Rigel.
In point of brilliancy Rigel ranks next to Capella. It is a very
bright blue-white star, as dazzling as a small electric light and as
sparkling as a fine diamond. But with all its fair beauty Rigel
docs not seem as much of a personage in the assemblage of stars
as sombre old red-faced Betelgeuse; and in looking at them I am
always conscious of feeling a somewhat closer friendliness for
Betelgeuse than for Rigel. This, however, is purely a personal
fancy.
With the exception of Deneb, Rigel and Betelgeuse are the
most distant of all twenty-one stars of the first magnitude. From
Rigel light takes 1300 years to reach us. From Betelgeuse it takes
500 years.
From the fact that Rigel and Betelgeuse, despite their distance,
are still first-magnitude stars, we must conclude that they are
intrinsically extremely bright. Enormous Betelgeuse, red and cool,
is about 17,000 times brighter than the sun. Rigel, blue-white
aiid extremely hot, though very much smaller than its nearby red
sister, is 150,000 times more brilliant than the sun.
Although Rigel rises about fifteen minutes later than Betel-
geuse it sets nearly two hours earlier. This is because it is farther
south than Betelgeuse and has a shorter path over which to travel
from rising to setting. Betelgeuse is above the horizon for some-
thing more than thirteen hours, while Rigel is in view only about
eleven.
Orion's Bright Stars 55
When on the meridian, Rigel lacks four degrees of being half-
way up to the zenith, and Betelgeuse lacks only four degrees of
being two-thirds of the way up. The course across the heavens of
Betelgeuse corresponds very nearly with that of Altair, The
course of Rigel is about the same as that of Spica.
The other bright stars of Orion are hardly less interesting
than Betelgeuse and Rigel. Bellatrix, which marks the left
shoulder of the giant, is of the second magnitude, but still a
very brilliant star. Three dazzling second-magnitude stars form
the belt, or girdle, of Orion and lie half-way between Betel-
geuse and Rigel. These are the stars supposed to be referred
to by Job as "the bands of Orion." They lie in a straight line
exactly three degrees long, and are rendered so conspicuous by
their position and their intrinsic beauty that they serve as an
aid in finding the constellation. They also provide a measure
for estimating distances in this section of the skies. The upper
one of them lies exactly on the celestial equator, and is a fine
double star discovered by means of the spectroscope.
These three stars are called in some places the "three kings,"
and the line formed by them is sometimes called the "ell and
yard" on account of its being just three degrees long.
Hanging from the belt is a curved line of stars known as the
sword of Orion. The central star of the sword is distinctly hazy
in appearance, and is no other than the famous Orion Nebula.
It is one of the finest nebulae in the heavens and one of the
few that can be seen with the naked eye. The one star that
we see in it resolves through the telescope into four beautiful
stars which form a figure sometimes referred to as the "Orion
trapezium."
The fourth star, Kappa, which with Betelgeuse, Rigel, and
Bellatrix forms the large parallelogram that outlines Orion's
body is called Saiph and is situated in the right knee of the
mighty hunter. Bellatrix signifies "Female Warrior" or "Amazon
Star." Saiph means "Sword," although this star lies at some dis-
tance from Orion's pendent dagger.
With all its wonders and its beauties, it is not strange that
Orion should be one of the most familiar and most admired of
all the constellations. It is in the center of the galaxy that
marches in brilliant procession across the winter skies. We
watch for it between nine and ten o'clock in the evening late
56 The Friendly Stars
in October, and our first view is of the curved line of faint
twinkling stars that outline the left arm and the shield of lion's
skin. Then one jewel after another emerges from the storehouse
below the horizon until the whole splendid figure is before us.
Its arrival is an announcement that the out-door season is past,
that the nights are becoming more and more frosty, and that
the gorgeous tapestry with which the autumn hills seem cov-
ered will soon fall away and give place to the lovely low tones
of winter. We remember then that the j uncos came that day
and that as we crossed the coppice about dusk we heard them
twittering cheerfully to each other as they settled for the night
among the low bushes. And we make a mental note to see to-
morrow if the little brown screech owl has moved into his win-
ter quarters in the old catalpa-tree across the road.
During November and December, Orion becomes a familiar
figure in the evening skies, rising a little earlier each evening
until during the week on each side of New Year's Day he ap-
pears in the east just as daylight fades. In February he stands
erect in the southern sky at nine o'clock in the evening. In March
and April he is rushing furiously down the western sky after
Taurus and the Pleiades, and by the middle of May he has dis-
appeared from the evening view. In the latter half of July the
very early riser can catch a glimpse of him in the east just before
daylight. It was, no doubt, in this month that the "rosy-fingered
dawn" took him for her lover, as she is reputed to have done.
XIII
The Heavenly Twins
ON the old astrological maps the constellation Gemini, or
The Twins, was represented by two lusty-looking youths
standing in an affectionate attitude with their heads practically
consolidated, and each wearing a star as a sort of monocle in
the outer eye. These stars are called Castor and Pollux, after
the brothers from whose eyes they are supposed to shine. They
are the brightest stars in the constellation Gemini, which is out-
lined by two almost parallel rows of stars beginning at Orion,
running northeast about twenty degrees, and ending with Castor
and Pollux.
Pollux is the brighter of the two and is the only first-magni-
tude star in the constellation. But it is almost as difficult to con-
sider the two heavenly bodies apart from each other as it was to
separate the two fond brothers for whom the stars were named.
The stars lie only about four and a half degrees apart and
are so conspicuously a pair that each serves as an identifying
mark for the other. Although 300 years ago Castor was reputed
to be brighter than Pollux, this is probably not so. Nevertheless,
Castor has some points of superior interest, as will be seen later
on, and is entitled to be considered with respect and admiration
in the gay company of our friends among the stars.
Castor and Pollux enter the eastern gate of the skies at about
the same time that Betelgeuse and Rigel appear, but the Twins
are so much farther north that there is no danger of confusing
them with the two brilliant stars of Orion.
Betelgeuse and Castor come into view at almost the same mo-
ment, the former only about seven and the latter a little more
than thirty-two degrees north of the exact east. About ten or
twelve minutes later Rigel appears at a point a little more than
eight degrees south of east, and after an interval of from ten to
57
58 The Friendly Stars
fifteen minutes, Pollux shines out above the horizon about thirty-
seven degrees farther north.
In November, when the twin stars first become a prominent
feature of the early evening sky, Castor is leading. When they
come to the meridian, about eight hours later, Pollux, being
farther south and thus having a shorter course to run, has so
gained on his companion that he reaches the meridian only about
ten minutes later. At this point, which is their highest, Castor is
nine-tenths and Pollux is about seven-eighths of the way up from
the horizon to the zenith.
As they descend the western sky Pollux makes a still further
gain, and in the latter half of the course they are seen side by
side. They are particularly attractive during all of May and
the first half of June, when they hang during the evening in the
northwestern heavens shining out gently and kindly from the
glowing background that the sun has left behind it.
Castor and Pollux were supposed by the ancients to exert a
favorable influence over navigation, and the figureheads of ships
often represented them. The Apostle Paul, when shipwrecked
on the island of Melita, sailed from it "in a ship of Alexandria
. . . whose sign was Castor and Pollux," and, of course, had a
prosperous voyage to his friends in Rome.
The constellation Gemini is the third spring sign of the zo-
diac, and it is easy to see how the mere beauty of its chief stars,
Castor and Pollux, may have fastened upon it the reputation of
responsibility for the beautiful weather that comes early in June.
At this season of the year position, atmosphere, and surround-
ings all combine to enhance the beauty and accentuate the
individuality of these two beautiful stars. All, save one, of the ra-
diant stars that have absorbed attention in this region of the sky
during the winter and early spring have disappeared. The rainy
Hyades, including Aldebaran, were the first to go. Stormy Orion
followed soon after, and the ill-omened Dog Star went with him.
And now in a comparatively starless environment the twin stars,
beloved of sailors, dominate the western sky and shine side by
side like two eyes benignly set to keep a protecting watch upon
the world. It is not the sailor alone whose fancy is pleased with
the kindly vigil they seem to keep. A landsman, too, may have
pleasanter dreams if he will but take a peep through the west-
The Heavenly Twins 5P
ern window and exchange friendly glances with them before
settling down for the night.
Inasmuch as Castor and Pollux are so closely associated in
our minds, in their times and seasons and their apparent posi-
tion in the sky, it may be something of a shock to learn that they
are in reality quite independent of each other and that they are
going each his own way, in entirely different directions, towards
an entirely different goal.
Castor is the farther of the two and is not very distant as
stellar distances go. Its light comes to us in around 47 years and
is about three million times farther from us than the sun. It re-
quires about thirty-three years for the light of Pollux to reach
us and the star is more than two million tunes as far from us
as the sun.
Castor and Pollux are not only widely separated, but they
are stars of very different spectral types. Pollux is yellow in color
and similar to the sun and Capella, whereas Castor belongs to
the large class of stars that includes Vega, Deneb, and about half
of all of the brighter stars in the sky. They are usually white,
though sometimes tinged with blue, as in the case of Vega. Some
observers say that Castor is tinged with green, although stellar
colors are probably not quite so finely differentiated.
Though the bond between Castor and Pollux is more apparent
than real, Castor, at least, has a true companion. The companion
is but a fraction more than one magnitude less bright than Cas-
tor itself and is greenish-yellow in color. It is bright enough to
be seen with the naked eye, but we cannot separate the two stars
without the aid of a small telescope because they lie so close to-
gether. The distance between them is only about four seconds,
or one nine-hundredth of a degree.
The two stars revolve about each other very slowly, and though
they were found nearly two hundred years ago to compose a
double system of stars, they have not yet completed one full
revolution, and their period is not exactly known.
Both of the principal stars composing Castor have been dis-
covered to be spectroscopic double stars. In addition to these
four stars, there is another small star near them that forms part
of the system; this faint member is again a double; and so
Castor is composed of six stars.
To swear by Castor and Pollux was common practice in an-
60 The Friendly Stars
*;ient times, and later the name of the constellation itself came
to be used in the same way. In Elizabethan literature we not in-
frequently find the expression "Oh, Gemini!" which by the
modern rustic is corrupted into a slightly different word and
gives him the expletive "By Jimmy!"
XIV
The Two Dog Stars
A STRAIGHT line from Aldebaran running through the
^ belt of Orion and extending beyond it towards the south-
east about twenty degrees will point out the Great Dog Star,
Sirius, by far the brightest star in the heavens, and, happily, so
situated that it can be seen in all southern latitudes and in all
northern latitudes south of Greenland. Next to Polaris it is,
perhaps, the best known of all individual stars, and this in spite
of its not being visible in the latitude of the United States be-
fore midnight during the months when people are most out-of-
doors and most likely to observe itfrom May to November.
Sirius is called the Dog Star because it is the chief star in the
constellation of the Greater Dog, which follows at the heels of
Orion in his journey across the skies. The constellation gives the
name of "dog-days" to the hot and trying period of the sum-
mer, including most of July and the first half of August. During
this time Sirius rises just after the sun, and following it over the
heavens each day, the star was supposed by the ancients to be in
some way responsible for the malign heat of the midsummer
sun and to exert an evil influence on the health of those exposed
to its burning rays. Even now we frequently hear that dogs are
likely to "go mad" at this season because "the Dog Star is in
the ascendant." Indeed, the name Sirius comes directly from a
Greek word signifying sparkling or scorching.
From Homer down to the present day few great poets whose
themes were of out-door things have failed to refer to Sirius. A
beautifully compact and comprehensive description of the star
and its characteristics is given incidentally in the Iliad, where
Achilles, mad with rage, was first seen by Priam "as he sped
across the plain, blazing as the star that cometh forth at harvest-
time, and plain seen his ways shine forth amid the host of stars
61
62 The Friendly Stars
in the darkness of the night, the star whose name men cal
Orion's dog. Brightest of all is he, yet for an evil sign is he set.
and bringeth much fever upon hapless men."
Sirius is the farthest south of any of the bright stars of wintei
that can be seen in this latitude, and in the sweep over its coat
paratively small arc in our skies it rises only about fourteen
degrees higher than Fomalhaut, the most southern of the im-
portant autumn stars, and ten degrees higher than Antares,
the most southerly fim-magnitude star of summer. When Sirius
is on the meridian, or at the highest point in its diurnal course
from rising to setting, it is only about one-third of the way up
to the zenith. It reaches this point about five hours after rising,
and, hence, is above the horizon only ten hours out of each
twenty-four.
We begin to look for Sirius in the evening sky about the mid-
dle of November, at which time it rises about ten o'clock. The
real activity of the year is over. No flowers are in bloom save
that here and there in some sheltered, sunny spot in the coppice
a belated aster is cheerfully swinging its bright blue-starred
branches, or some other flower whose season is long past has
been enticed by the warm sunshine into showing yet one more
blossom. To be sure, the witch-hazel, the very last flower of the
year, which thriftily puts forth in the late autumn the bloom
for next year's fruit, hangs full of the curious, straggling golden
threads that constitute its flowers; but it stands bare of leaves
and its empty seed-cups are open-mouthed as if with wonder
and admiration at the success of the explosions by means of
which it has lately peppered the neighborhood with its fruit.
The heavy frosts have finished the work of painting the hills;
the rich brown leaves are fast piling their soft winter covering
over the yet warm earth; the smooth dean juncos have been
flirting around in merry group for three or four weeks, and the
lovely Indian summer haze hangs like a soft mantle of gauze be-
tweea us and the half-denuded trees.
In the skies all of the other bright winter stars have arrived,
and some of the brightest of the spring and summer stars still
linger to grace the company, when the king of stars arrives. No
less than ten of our sixteen brightest stars are in view when the
dazzling face of Sirius appears. On the eastern side of the hea-
vens are golden Capella, rose-tinted Aldebaran, red-faced Betel-
The Two Dog Stars 43
geuse, fair Rigel, the gentle Pollux, and Procyon, the smaller
Dog Star, all fresh and joyous and eager. In the southwest is
Fomalhaut, serene and indifferent to what is about to transpire.
In the west is Altair, just waiting above the horizon to witness
the event and then drop out of sight. In the northeast are Vega
and Deneb, bright and gay and twinkling with almost as many
hues as Sirius himself.
He comes rich in many colors, twinkling fast and changing
with each motion from tints of ruby to sapphire and emerald
and amethyst. As he rises higher and higher in the sky he gains
composure and his beams now sparkle like the most brilliant dia-
mondnot a pure white, but slightly tinged with iridescence. It
is worth enduring the chilliness of a clear, mid-November night
at ten o'clock to see the assemblage of these eleven noble stars
with their attendants. For mere brilliancy the celestial view is
surpassed at no other season of the year.
Whereas Sirius is now white in color, some early references
have indicated that a few thousand years ago it might have been
red. Study of these passages, however, indicates that the proper
translation is "fiery" rather than "red." It could scarcely be pos-
sible that a few thousand years, though a long time in the his-
tory of mankind, could possibly have led to major changes in the
physical characteristics of a star like Sirius.
On Thanksgiving evening, which so often marks the first cold
"snap" of the season, Sirius rises about nine o'clock. On Christ-
mas evening it becomes visible a little after seven, and on New
Year's about half an hour earlier. About the twenty-eighth of
January it rises just as the sun sets, not far from five o'clock.
Being so low in the sky, it is easily observed at any point in its
course. Except for the first thrill of pleasure that it gives when
it appears in the late autumn, Sirius is never more attractive
than during March and April. It is then at its highest during
the early evening and shines brilliantly in the southwest. It sets
with the sun about the twentieth of May, and for some days be-
fore that it has been invisible, its light being lost in the rays of
our own great orb.
Sirius is one of the stars that we know to be comparatively
near to us. Light travels from it to us in about eight years and
a half, which means that it is about fifty-one trillions of miles
distant, or more than five hundred thousand times farther away
64 The Friendly Stars
than the sun. We get from the star only one seven-billionth of
the light that the sun gives us; but Sirius in reality gives out
about forty times as much light as the sun. It is a very gaseous
and expanded body, however, and though very much larger and
more brilliant than the sun, is comparatively light in weight, its
mass exceeding that of the sun only about three times.
Sirius has a very interesting companion, which revolves around
it in a period of fifty years. Its orbit is such that the two stars
are nearer together at one time than at another, and it is only
when they are farthest apart that the companion can be seen,
and even then a strong telescope is necessary. When at their
nearest, the companion is so completely lost in the brilliant light
of Sirius that it cannot be found at all. The existence of such a
companion had been long suspected, but it was not actually dis-
covered until 1862, a year when the distance between the stars
was increasing.
The faint companion is white in color, a fair match to Sirius.
From this fact one deduces that their surface temperatures are
about the same and that the stars have identical surface bright-
nesses. Since Sirius gives about 3,000 times as much light as its
companion, we must further conclude that the companion is
very tiny, scarcely laiger than our earth. The mass of the fainter
star, which is about half that of Sirius, is thus compressed into
a very small volume A teaspoonful of the highly condensed mat-
ter of such a white dwarf would weigh a ton. Such compression
is characteristic of white dwarfs, which are believed to represent
stars in the final stage of their history.
The other Dog Star, Procyon, lies in the constellation of the
Little Dog (Canis Minor). To locate Procyon, run a line a little
more than twenty degrees northeast from Sirius, or about the
same number of degrees east from Betelgeuse. Procyon, Sirius,
and Betelgeuse are at the angles of an almost equal-sided tri-
angle, and the same three stars form with Rigel a figure that is
almost a square. Procyon is twenty-three degrees directly south
of Pollux and forms a triangle on the north with Pollux and
Betelgeuse of just about the same size as the triangle it forms
with Betelgeuse and Sinus on the south. It rises an hour and a
half later, aiad sets an hour and a half earlier, than Pollux.
The name Procyon means "before the dog" or, more literally,
"precursor of the dog/' The star received this name because it
The Two Dog Stars 65
appears in the east from fifteen to twenty minutes before the
Great Dog Star. It rises very little north of the exact east, reaches
the meridian about six hours and twenty minutes later, and sets
between two and three hours after Sirius. At its highest point it
reaches about three-fifths of the way up to the zenith.
Procyon suffers somewhat in reputation by reason of its con-
nection with Sirius. The fact that it is known as "the other Dog
Star" and "the Little Dog Star" indicates inferiority of some
sort. It is, in fact, a most beautiful star, and is only the sixth in
order of brightness among the stars seen in our latitude. It is
very distinctly individual, being the only one among the beauti-
ful group of winter stars that is lightly tinged with yellow. Pro-
cyon is definitely cooler than Sirius and in some ways resembles
the sun, though it is considerably brighter.
Procyon is also one of the near-by stars, but it is not so near
as Sirius. Light travels from it to us in a little more than eleven
years; so that the star is about seventy trillions of miles away
from us. It gives out six times as much light as the sun, and is
in no sense an insignificant body or one to be known only as
announcing the imminent arrival of Sirius.
Procyon also has a companion of its own, a yellow-white star
of about the eleventh magnitude, which revolves around it in
about 40 years. It is a matter of coincidence that, like the com-
panion to Sirius, the body accompanying Procyon is also a white
dwarf. In other words, the faint companions to both of the dog
stars are the enormously dense white dwarfs. The companion
of Procyon was not discovered until 1896.
XV
Regulus
'T'HERE is no single line by which Regulus can be exactly
pointed out to one who does not know the constellations.
Still it can be easily found. A line forty degrees long drawn
through the pointers backwardthat is, away from the North
Star will end just a little to the west of a conspicuous group
of stars known as the Sickle (and really resembling that instru-
ment) , and Regulus is the brilliant jewel that sparkles at the
end of the handle.
In June and July, when Antares and Spica are both shining,
Regulus may be found by a line drawn from Antares through
Spica and extended about fifty degrees. The line will unmistak-
ably indicate Regulus, but the star will be well down in the west
and not far from setting. When Arcturus is visible and not too
far down in the west, Regulus may be found at a point about
sixty degrees west (a very little north of west) of Arcturus. A
triangle is formed by Spica, Arcturus, and Regulus, with Regu-
lus at the acute angle pointing towards the west.
Among the brightest stars, Regulus comes and goes rather
between seasons. It is not strictly a summer star or a winter star,
though it may be seen in both seasons. It is, in fact, visible at
some time between sunset and midnight for eight months in the
year. It arrives after the galaxy of brilliant winter stars are in
full swing across the heavens and before the gay company that
gladdens our view in the spring has begun to assemble. It ap-
peais above the horizon a very little north of east about nine
o'clock in the evening of New Year's Day. One may even have
seen ii a little later in the evening than this some days before
Christmas; but Regulus does not have the insistent quality of
brightness that commands the regard of the ordinary observer
66
Regulus
until it has reached a position and an hour when one can ob-
serve it conveniently.
From the time it first attracts our attention until Arcturus and
Vega come, Regulus is the chief ornament of the eastern skies
and shines like a veritable diamond of the highest quality, fit to
be set in the jewelled hilt of sword or scimitar of fine Damascus
steel rather than the handle of a homely garden implement. It
is a singularly dear, white, sparkling star, with just a touch of
blue. But in spite of its brilliancy it seems a much smaller point
of light than many of the bright stars. It is next below Deneb
and Beta Crucis in its rank among the stars as to brightness, and
the stars are so nearly equal that some astronomers have given
Regulus the highest place. Modern photometry, however, ranks
it sixteenth in order of brightness among the stars visible in the
northern hemisphere. It ranks twenty-first among all the first-
magnitude stars.
It requires about six hours and three-quarters for Regulus to
reach the meridian, and it is then about one degree more than
68 The Friendly Stars
two-thirds of the way up to the zenith, or the point exactly over
our heads. It shines all night in January, February, March, and
April, rising in February just as the sun sets. In May, June, and
July it may be seen travelling towards the western horizon dur-
ing the first half of the night. By August it is so near the sun
that even with a favoring atmosphere we can barely get a glimpse
of the star during the first few days of the month, as it falls be-
low the horizon dose after the sun; and it remains in this region
most of September. In the early morning hours of October and
November it may be seen gradually gaining on the hours until
it comes back to its familiar place in the east.
Blue-white Regulus is a trifle hotter than Vega, Deneb, or
Sirius, but not quite as hot as Spica. It certainly ranks among the
stars having high surface brightness. Regulus is about 140 times
brighter than our sun, and its distance from the solar system is
so great that we do not receive the light from the star for some
77 years after it has started toward us, moving though it does at
the enormous rate of 6 trillions of miles a year.
Regulus is in the constellation called Leo, or the Lion. The
blade of the Sickle marks the shoulder of the Lion, and Regulus
lies at its heart. The star is sometimes called "Cor Leonis," mean-
ing "the Heart of the Lion/* The name Regulus means "chief."
The constellation Leo is one of those that the sun passes
through in its apparent annual path across the heavens. The
sun stays in this constellation a little more than five weeks, en-
tering it at the beginning of the second week in August. Two
weeks later the sun passes Regulus, and as the star lies almost
exactly in the path of the sun, they would seem to an observer
on the earth to almost touch each other. But at this time the
light of Regulus is lost in the sun's rays, and we do not see this
interesting meeting.
Another interesting star in Leo, though not of the first mag-
nitude, is Denebola. It marks the tuft at the end of the Lion's
tail, and its name means "the Tail of the Lion." It lies about
twenty-five degrees east of Regulus and a very little to the north
of it It is the brightest star in a small triangle which a glance
towards the region indicated will reveal. A small telescope shows
Denebola as a beautiful double star of contrasting colors. The
pair does not form a physical system, however. The stars do not
Regulus 69
revolve around one another but lie merely in the same direction.
Within the curve of the blade of the Sickle is the point from
which the meteors that come along in the middle of November
seem to radiate. They are on this account called "Leonids."
XVI
The Number of the Stars
/^\N a dear starlit night the sky seems so thickly set with stars
that, on first view, it is difficult to believe that within two
hours one could count every one of them. Yet this is true, tor
to the ordinary eye there are not more than a thousand stars
visible at one time. The very keenest eye without mechanical
assistance cannot discern in the heavens, north and south, more
than seven thousand, and barely five thousand are visible to the
ordinary sight. Of this entire number nearly one-fourth are too
far south to be seen at all in our latitude; and of those that can
be seen here only one-half are visible at once, the others being
below the horizon and visible only in the other hemisphere. And,
finally, of those that are really above the horizon and could oth-
erwise be seen, the bright stars are somewhat obscured by the
dense atmosphere while near the horizon, and the faint ones are
completely blotted out for a considerable distance farther up.
This is why there seem to be no faint stars low down in the sky.
In reality they very largely outnumber the bright ones in every
part of the heavens, but they can be seen only when they rise
high enough to escape the heavy lower atmosphere.
The stars that we can see with the naked eye (astronomers call
them lucid stars) are, of course, a very small proportion of the
total number of stars in the universe. As to the total number of
stars within our galaxy, astronomers generally believe that there
must be approximately 100 billion. It is estimated that the larg-
est telescope will reveal approximately 2 billion. Remember,
these are just the stars of our own galaxy. When we realize that
tbesne may be as many as a trillion galaxies accessible with laige
telescopes, each containing perhaps as many stars as our own
galaxy, the total number of stare proves to be tremendous.
The difference of opinion among astronomers as to the limi-
70
The Number of the Stars Jl
tation of the stars is based in part upon their ideas of the de-
structibility of light. It is certain that we do not get an infinite
amount of starlight. If we did, all space, they say, would be filled
with a diffused glow and there would be no such thing as dark-
ness. For it is not necessary that we should actually see the stars
individually in order to have light from them. Those that we
can see with the naked eye give only about ninety per cent of the
total starlight received by us. The naked-eye and the telescopic
stars combined give only about one one-hundred-and-eightieth
as much light as the full moon. But on a bright starlight night
the light we receive is equal to about one-sixtieth of full moon-
light, which shows that we get three times as much light from
the stars whose rays are too faint to be seen as from all the other
stars together.
It has been shown by photography that we get light from stars
that are invisible to the eye in even the largest telescope. The
photographic plate has an advantage over the eye in that the
plate can store light as the result of a long exposure. The eye,
on the other hand, has no storage capacity. In fact, because of
fatigue, the eye, used continuously over a period of time, usually
sees less at the end of that interval. The faint stars, so recorded,
which will ever be invisible to the less sensitive human eye, are
nevertheless contributing light to the sky, for they would make
no impression on the photographic plate if their light did not
reach it.
Observations have shown that interstellar space contains a
certain amount of fine dust particles. The amount of dust in
any given volume of space is relatively small, however. If we
used a vacuum cleaner to sweep out a volume as large as our
earth, for example, of even the dustiest regions, we should collect
at most about a cupful of dust. Even so, distances in inter-
stellar space are so vast that, in certain regions, the dust ap-
preciably dims the stars. Our Milky Way would be much brighter
if dust clouds did not obscure the stars behind them.
Einstein's theory of relativity has indicated that space is not
infinite. At great distances, a natural curvature of space tends
to limit the volume. Hence, the number of stars, either in our
own galaxy or in other galaxies, cannot be infinite.
There are certain bodies in space which, for want of a better
name, we speak of as dark stars: that is, stars that give no appre-
72 The Friendly Stars
ciable light. They make themselves known in some instances by
passing at regular intervals between us and a bright star, thus
showing that they are revolving around it. In other cases they
make the star swerve from what its course would naturally be,
thus showing the influence of some invisible body. Most of these
so-called dark stars, however, are not completely dark. But there
well may be many dark bodies in space, either dead stars or cold
matter like our planets or meteors. But at present they need not
be taken into account.
The telescope and camera both give evidence of a limit at
least to the number of the stars that we can really know. As
telescopes were made larger and larger a greater number of stars
became visible; and it seemed as if the number we could see
depended solely upon the power of the glass. It has been found,
however, that beyond a certain point the number we can see
does not increase in proportion to the increased size of the tele-
scope. This indicates that we must be approaching the limit of
the number of stars that send their light to us. The same thing
is shown by the camera. After a certain length of exposure, ad-
ditional time will add no more than a few stars to the number
already on the plate
There are about twenty well marked degrees of brightness in
the stars seen through the largest telescopes. For the first ten or
twelve of these the number of stars in each grade is about three
times greater than in the grade preceding it in order of bright-
ness. That is, we have of the first degree of brightness twenty-one
stars; of the second degree, about sixty; of the third, one hundred
and eighty, and so on. But after about the twelfth degree of
brightness the number of stars does not increase in the same
proportion; the increase as shown by both the telescope and the
camera is comparatively small.
It is not to be supposed that, because telescopes and the cam-
era have not yet revealed them, astronomers think there are no
more stars to be discovered. But the evidence of the telescope
and photography shows we are approaching that limit. The
exact number will probably never be known. Certainly it will
never be known by means of the telescope; for we seem to be
ircadung a point where it will be physically impossible to make
lai^er telescopes that can be effectively used. The last extension
of our knowledge of the number of the stars will probably be
The Number of the Stars 73
reached only indirectly. For, even if we cannot see the stars in-
dividually, their collective gravitational effects may be sufficient
to influence the motion of visible stars in that region of the sky.
The more rapidly the stars move the greater the mass of these
invisible stars. But even by this method we cannot infer the ex-
istence of truly enormous quantities of invisible, undiscovered,
dark matter.
What is not recorded on the photographic plates of the future
will remain to us unknown. We can be reasonably sure of only
one thing: that, in view of the evidence we have of the decrease
in the number of the stars as they grow fainter to us, the ones
remaining undiscovered are practically but a few stragglers along
the "fringes of the visible universe" few, even though there may
be really many millions of them.
While the number of stars that are known is increasing some-
what all the time, astronomers are not so much trying to make
discoveries of larger numbers as to learn something more about
the stars that are already known. The number now classified and
catalogued is something near eight hundred thousand.
A great international photographic chart of the heavens,
completed with international cooperation, showed more than
40,000,000 stars. And the greatest survey of all, a series of photo-
graphs taken with a powerful Schmidt camera at Palomar Ob-
servatory, has revealed so many stars that no accurate census of
their number is available. Unfortunately, this Palomar survey
covers only the stars visible from the northern hemisphere. A
similar survey for stars in the vicinity of the south celestial pole
will probably be completed in the next few years.
XVII
The Names of the Stars
"LTAPPILY for the interest of the ordinary observer, nearly all
the brighter stars, and a few of the fainter ones, have indi-
vidual names. Sixty or more of these names are in common use
even among professional astronomers. Most of these belong to
the so-called navigational stars, the stars that navigators observe
to find their positions on the sea or in the air. A few more names
are well known and are used occasionally, and a number which
are now practically obsolete appear in old catalogues, or his-
torical lists, or in some piece of ancient literature. Less than a
hundred names will cover all the stars of the first and second
magnitudes; and besides these there are not many that have an
individual interest for an observer without a telescope. When
one learns to know fifty or sixty stars so that he can always recog-
nize them and call them by name, he begins to feel that he has
a pretty large acquaintance in the heavens; and the knowing of
other individuals that may chance to interest him is then the
mere matter of an introduction.
Most of the individual stellar names originated with the ancient
astronomers and have a meaning that describes some char-
acteristic of the star, some trait, or color, or position in the con-
stellation. All of them were probably descriptive at first, but the
original meaning is not always dear. Sometimes designation was
made by a drcumlocution such as "the Heart of the Lion," "the
Eye of the Bull/' "the Foot of the Giant." This was, of course,
too cumbersome and limited a method to answer the needs of
modern astronomy. But many Latin and Arabic names are still
used which in one word describe the place the star holds in its
constellation; as, for instance, Achernar, meaning "the End of
the River," and Denebola, "the Tail of the Lion."
Very early in the seventeenth century, astronomers adopted
74
The Names of the Stars 75
the plan of designating the stars in each constellation by the
letters of the Greek alphabet and adding the name of the con-
stellation in its Latin form in the genitive (or possessive) case,
thus making the name of the constellation a sort of family name
for all the stars composing it, and the Greek letters the given
names. Thus in the constellation Taurus we have Alpha Tauri,
meaning Alpha of Taurus; Beta Tauri, Gamma Tauri, and so
on. When the Greek alphabet was exhausted, the Roman letters
were used. Beginning with alpha, the stars of each constellation
were named in the order of their brightness. In the main, though,
when several stars in the constellation chanced to be of nearly
the same degree of brightness, there seems to have been no nice
distinction made between them. A major exception is the Big
Dipper, whose seven bright stars cany the Greek letters from
Alpha to Eta in order from bowl to handle.
A century later another catalogue was made, and in this num-
bers were used instead of letters for the given names, the geni-
tive case of the constellation still being used as a family name.
Several special catalogues have been made in which also the stars
are indicated by numbers, such as Lalande's, the British Associa-
tion Catalog, the Harvard Photometry, and the Henry Draper
Catalog. In such cases the reference is simply by number and
name of catalogue. Some stars that have in a way become famous
by reason of some individual peculiarity or characteristic still
have no designation except by number. Among them, and spoken
of more particularly elsewhere in this book, are 61 Cygni, 1830
Groombridge, and some others. Stars are also designated by their
position in the heavens, which is expressed in the terms of astro-
nomical measurements, right ascension and declination, the ce-
lestial analogs of terrestrial longitude and latitude.
A result of these various methods of naming the stars is that
nearly every bright star is designated in several different ways: by
its individual name, its Greek letter name, its number in the
various catalogues, and its position in the heavens. But the ordi-
nary observer need not much trouble himself with learning them
all. One can have an intimate knowledge of nearly all the naked-
eye stars without once resorting to figures for names, or without
even knowing what right ascension and declination are. Astron-
omers have evolved these several schemes of designation only for
their own special needs. Rarely has a star known only by its num-
J6 The Friendly Stars
her become, for any reason, of general interest. There are not
now more than half a dozen such stars. Probably 61 Cygni (that
is, the star numbered 61 in the constellation of the Swan, or Cyg-
nus) is the best known of these, because it is the first star whose
distance from us was measured. Despite its nearness, however,
it is of magnitude 5.5, one of the fainter naked-eye stars.
The method of designation most common among writers cm
astronomy for the brighter stars (when the individual name is
not given) is that of the Greek letter joined to the name of the
constellation. After the constellations are once known, this is an
easy method, and, even for the non-professional observer, has
several advantages. It not only names the star, but assigns it to a
constellation, and gives an approximate idea of its degree of
brightness as compared with other stars, and particularly as com-
pared with other stars in the same constellation. Alpha of a con-
stellation is almost always the brightest star in the group. The
exceptions to this are few and mainly accidental. One instance is
that of Castor and Pollux, the two bright stars of the constella-
tion Gemini, or the Twins. Pollux is the brighter of the two, yet
Castor is Alpha Geminorum and Pollux is Beta GeminorunL
It is not often that the average reader will care, or need, to
know the names of more than the seven or eight brightest stars
of a constellation, the ones designated by the first seven or eight
letters of the Greek alphabet: alpha (a), beta (), gamma (y),
delta ($), epsilon ( c ), zeta (), eta (^), and theta (0). Rarely,
indeed, will he care to know even that many. In the Great Bear
(Ursa Major) the seven brightest stars, the ones that form the
well-known Dipper, are of almost equal importance and bril-
liancy. But this is an exceptional case, and more often only three
or four stars in a constellation, the alpha, beta, gamma, and
delta of the group, have any special interest. Occasionally one
of the fainter stars calls for particular attention, as in the case of
Mira, the Wonderful, in the constellation of the Whale, or Cetus,
which is designated by the fifteenth letter of the Greek alphabet,
onucroa, thus: o Ceti.
The Greek letter method of naming the stars has, then, its
conveniences. But, after all, when a star, like anything else,
conies to have any special individuality for us we desire a name
for it that is all its own. When we come really to know splendid
Arcturus, we do not care to call him Alpha Bootis any more than
The Names of the Stars 77
we want to call a dainty spring beauty Claytonia vtrgsnuo, or
the golden-eyed white daisy Chrysanthemum Leucanthemum.
And, happily, we are not often put to this discomfort, for there
is no star of the first magnitude in the northern hemisphere that
has not an individual name. In the southern hemisphere, how-
ever, Alpha Centauri, Beta Centauri, Alpha Crucis, and Beta
Crucis are more commonly referred to by their Greek-letter
designations than by their proper names, which are Rigil Ken-
taurus (or simply Rigil Kent), Hadar, Acrux, and Becrux, re-
spectively. The last two names are specially coined to designate
the stars for navigational purposes. Alpha Centauri, we have
seen, is the star that is nearest to us.
I remember feeling distinctly grateful to the old astronomers
for having given individual names to much less conspicuous or
important stars. A window in my bedroom opens out towards
the northeast, and during the autumn and early winter the
Dipper is visible there a good part of the night. Many times it
has happened that I have suddenly opened my eyes in the night
and found there beaming down upon me the soft rays from the
star Mizar, which lies just in the bend of the handle of the
Dipper and next to the end star, and its tiny companion Alcor,
that seems to send its own little beams almost along the same
path. The simple friendliness that I felt in encountering them in
this way came as much, I think, from my being able to greet
them by their own names as from their intrinsic beauty and
steadfast cheerfulness.
XVIII
The Light of the Stars
CTARS are classified according to their brilliancy into magni-
tudes; and as applied to them, the word magnitude has a spe-
cific meaning. It has reference solely to their brightness and has
nothing to do with their proportions. Many stars that appear to
us very small and faint we know to be of immense size, far ex-
ceeding some of the most resplendent stars of the heavens; so
there is no simple relation between the real and apparent magni-
tude of a star that is, between its size and its brilliancy.
This use of the word magnitude was fixed in astronomy in the
early days of the science, before the telescope had been invented
and before there was any way of judging of the dimensions of a
star other than by its appearance to the naked eye. The stars
that seemed the largest and brightest were supposed really to be
so, and were said to be of the first magnitude; the next brightest
were called second magnitude stars, the next third magnitude,
and so on. All the stars visible to the naked eye were divided
according to their lucidity into six magnitudes, and modern as-
tronomers have found it convenient to continue this way of de-
scribing their comparative luminous power, and have applied
the same principle in describing telescopic stars even below the
twentieth magnitude.
It is, of course, an arbitrary classification, for there are stars
of every degree of brightness between Sirius, the brightest star
in the heavens, and the faintest star we can see; and, so far as
accuracy is concerned, we might as well have had sixty magni-
tudes among the visible stars as six. Moreover, with no more ac-
curate measurement than one can make with his eye, it is not
easy for the ordinary observer to tell the difference between the
amount of light we receive from a faint star of one magnitude
and a bright one of the next lower magnitude. Since naked-eye
observation was the only way of determining stellar magnitudes
The Light of the Stars 79
among the ancient astronomers, there was considerable differ-
ence of opinion concerning the brightness of such stars as were
on the border lines of each magnitude. To the first magnitude
there were assigned anywhere from fourteen to twenty stars, and
in the lower magnitudes the difficulty of agreement was even
greater.
Modern astronomers, while retaining the old method of clas-
sification, have endeavored to systematize it by the accurate
measurement of the amount of light we receive from each star.
This is done with an instrument known as a photometer, by
means of which- very slight gradations in the light of the stars
can be determined. With this instrument practically all the
naked-eye stars have been measured, and they have been cata-
logued accordingly. Modern photoelectric photometers are ex-
tremely accurate and sensitive. They are capable of recording
gradations of brightness as small as one one-thousandth of a
magnitude.
In making the measurements, the astronomer adopts some
standard of light, compares the light of each star with that standard
and then determines the stellar brightness in terms of the basic scale
of magnitudes. In the Harvard Photometry, the Pole Star (Polaris)
was originally the adopted standard star taken for comparison.
It is a conspicuous and important star that everyone knows, and
has long been rated as of the second magnitude even in the
days of rough judging of the brightness of stars. Unfortunately,
however, Polaris is slightly variable. To extend the photometric
scale to fainter magnitudes and to provide standards of com-
parison that would always be visible from the northern hemi-
sphere, astronomers have measured very carefully the brightness
of a number of stars in the vicinity of Polaris. These form the
North Polar Sequence. Now, when an astronomer wants to
determine the brightness of some particular star in the sky, he
measures it very carefully with a photometer and then turns to
the North Polar Sequence for checking and standardizing his
measures.
One would think that the determination of stellar magnitudes
would have been based on either the brightest star or one of the
brightest as a standard and that all other stars would have been
graded from that. This is probably what would have been done
if the stars had not been classified as to brightness until the
SO The Friendly Stars
delicate instruments for measuring their light were invented. As
it is, the classification was made many hundred years ago, and
though modern astronomers are endeavoring to express the com-
parative gradations of light as accurately as possible, they still do
not much disturb the distinctions that have long been familiar.
By photometric measurements the gradations of light between
the different magnitudes are expressed in tenths by decimal frac-
tions. Thus the magnitude of one star is 2, that of another a little
less bright is 2.1, and so on to 2.9, which is almost as faint as a
star whose magnitude is 3. The larger the fraction the nearer the
magnitude of the star is to the next magnitude below the one in
which it is classed, and the higher the number of the magnitude
the fainter the light of the star.
For the ordinary observer it is sufficient to know that a star is
of the first, second, third, or whatever magnitude, as the case
may be. These nice distinctions in tenths between degrees of
brightness are useful more to the serious student than to the gen-
eral reader. The usual way of classifying is to designate a star as
of the magnitude to which it is nearest. Consequently each mag-
nitude reaches out on each side and takes in all stars that are not
more than five-tenths of a magnitude from it. For example, all
are called first-magnitude stars whose magnitude is brighter than
1.5. If a star's brilliancy is found to be 1.6, it is classed as a second
magnitude star, and all are of the second magnitude from this
down to 2.5; and similarly the other magnitudes are reckoned.
This is true of all the magnitudes except the first. This has its
limits only on one side. It includes all stars that are brighter
than 1.5 magnitude. There are but twenty-one stars of the first
magnitude, but the individual lustre of them varies so as to cover
nearly three magnitudes. To overcome this difficulty astronomers
express the magnitude brighter than 1 as 0, the magnitude next
brighter as 1. The magnitude of Sirius, the most brilliant of
all the stars, is 1.42. Alpha Crucis, Spica, and Antares, all
of the southern hemisphere, are almost exactly first-magnitude
stars. Five others are less bright than Antares, and twelve are
between Alpha Crucis and Sirius.
According to the most recent photoelectric measurements,
the visual magnitudes of the twenty-one brightest stars are as
follows:
The Light of the Stars 81
Sinus (Alpha Canis Majoris) 1.42
Canopus (Alpha Carinae) 0.72
Alpha Centauri . 0.27
Arcturus (Alpha Bootis) , 0.06
Vega (Alpha Lyra) +0.04
Capella (Alpha Aurigae) 0.05
Rigel (Beta Orionis) 0.14
Procyon (Alpha Canis Minoris) 038
Achernar (Alpha Eridani) 0.51
Beta Centauri 0.63
Altair (Alpha Aquilae) 0.77
Betelgeuse (Alpha Orionis) 1 1 i S^."
Aldebaran (Alpha Tauri) 0.86
Alpha Crucis 0.9
Spica (Alpha Virginis) 0.91
Antares (Alpha Scorpii) 0.92
Pollux (Beta Geminorum) 1.16
Fomalhaut (Alpha Piscis Austrini) 1.19
Deneb (Alpha Cygni) 1.26
Beta Crucis 1.28
Regulus (Alpha Leonis) 1.36
The light ratio agreed upon between the different magnitudes
is 2.5. That is, a standard star of each magnitude is two and a
half times brighter than a standard star of the next lower mag-
nitude. Or, to put it the other way, each magnitude is four-
tenths as bright as the next higher magnitude. This makes a
first- magnitude star one hundred times brighter than a sixth-
magnitude star, and a sixth-magnitude star ten thousand times
brighter than one of the sixteenth magnitude. In the same ratio,
a first-magnitude star would be nearly four hundred thousand
times brighter than a fifteenth-magnitude, and thirty-seven mil-
lion times brighter than a twentieth-magnitude. This would
make Sirius something over two hundred million times brighter
than the faintest star of the twentieth magnitude.
But notwithstanding this vast superiority in brilliancy of the
brightest stars, we get more starlight from the faint stars as a
whole than from the bright ones as a whole. This is on account
of the large number of the faint stars; for it has been found that
the number of stars of a given magnitude is about three times
greater than the number of stars of the next brighter magnitude.
Hence, though a first-magnitude star is two and a half times
brighter than a second-magnitude star, there are three times as
many second-magnitude stars, and consequently we get more
light from them as a whole. Though a first-magnitude star is
82 The Friendly Stars
three thousand times brighter than one of the tenth magnitude,
yet there are seventeen thousand times as many of the tenth
magnitude as of the first. This progressive increase in number
is an approximate estimate, but it is deduced from actual cata-
logues of the stars and is fairly accurate. As previously noted,
however, the increase in number of three times between one
magnitude and the next holds only for the brighter stars. The
ratio decreases toward the fainter stars.
According to this ratio of progression, if one makes due al-
lowance for the way in which one magnitude merges into an-
other, the six or seven thousand stars visible to the naked eye are
distributed roughly as follows:
21 stars of the first magnitude,
60 " " " second "
180 " " " third
500 " " " fourth
1500 " " " fifth
4500 " " " sixth
Thus the total number of stars visible to the naked eye is
about 7000. How many stars one really sees of this seven thou-
sand depends upon the state of the atmosphere and the keen-
ness of one's sight. Smoke, dust, haze, or even the scattering of
light by a transparent atmosphere greatly reduces the bright-
ness of stars toward the horizon, for one is looking through
increasing thicknesses of air. As a result, most persons under ordi-
nary conditions fail to see nearly two thousand of them, and it
takes an eye of remarkable power to see them all. However many
one sees, there are always many more just on the verge of visi-
bility that seem to come and go. This is one reason why there
seem to be so many more stars in view than there really are.
It is to be remembered that all this applies only to the stars
as we see them, and has no relation to their real size or their
light-giving power. They may be brighter because they are nearer
to us, or because they are really more brilliant and give out more
light than others; but none of these qualities is determined by
their apparent luster. As a matter of fact, some of the brightest
stars are very well known to be not the largest.
On the average, of course, the brightest stars tend to be the
nearest to us, though there are many exceptions. The converse
The Light of the Stars 83
of this statement is far from true, however. The stars nearest to
us, with a few exceptions, do not tend to be among the brightest.
This paradox we can easily resolve. A given volume of space has
in it only relatively few very luminous stars, but it has enormous
numbers of stars whose luminosity is very low. For us to be able
to see these intrinsically faint stars they must be extremely close
to us. Thus, of the seventeen nearest stars, ten are too faint to
be seen with the naked eye and one of them, Wolf 359, is of
magnitude 13.5, a thousand times too faint to be seen without
telescopic aid. The intrinsically bright stars, however, are in-
tensely luminous and can be seen to enormous distances. Even
though they are relatively rare in a given volume of space, the
total volume through which they are visible is enormous. As a
result, it is safe to say, that with a few exceptions, most of the
stars visible to the naked eye are fairly distant suns. The best
known exceptions to this rule include Alpha Centauri, the near-
est star, Sirius, and Procyon.
XIX
The Distances of the Stars
HP HOUGH astronomers had been working for many years on
the problem of determining the distances of the stars, it
was not until 1838 that they succeeded in getting what seemed
to be any fairly accurate measurements. In that year the distance
of 61 Cygni was measured with reasonable correctness; and at
about the same time it was found that Alpha Centauri was even
nearer than 61 Cygni. Strangely enough, these two stars are still
counted among our nearest neighbors. The faint companion of
Alpha Centauri, of the eleventh magnitude, has proved to be a
member of that system. It may be a trifle nearer to us than Alpha
Centauri and hence has sometimes received the name Proxima.
The assignment of such a name is tempting fate. But, curiously
enough, the name may be justified. However, it is well within
the realm of possibility that, among the millions of still fainter
stars on our photographic plates, may be found one or more that
lie still nearer. If such a star is discovered, of course, the name
Proxima will then have to be completely discarded.
For many years 61 Cygni was supposed to be the next nearest
star. However, in the meanwhile, at least seven stars have been
found to lie closer than 61 Cygni, among them the brightest
star in the sky, Sinus.
The distances of a number of stars have been determined
since 1839; and through their knowledge of the distances of
these, asmmomers have been able to at least place limitations
on the distances of others, and taking color, brightness, and
other characteristics into consideration, have made inferences
also as to size and constitution which it seems reasonable to be-
lieve are very near the truth. The ascertainment of distances has
opened up a very large field of investigation; for, until the dis-
tance of a star is known, we can know but little of its size or
84
The Distances of the Stars 85
light-giving power, and hence little of its real nature, though its
chemical constitution may be revealed by the spectroscope. Two
stars may be apparently of equal brilliancy, but when we learn
that one is many times farther from us than the other, we rea-
lize how much brighter the more distant one must be. Take, for
instance, the two brightest stars, Sirius and Canopus. They are
both so much brighter than a standard first-magnitude star that
they are really in a class by themselves, though called first-mag-
nitude stars. Sirius is the brighter of the two, and it is five hun-
dred thousand times farther from us than the sun. Canopus is
so far away that it successfully resisted, for a long time, all efforts
of astronomers to measure its distance. Finally, special techniques
solved the problem and it was then found that Canopus is in-
deed one of the most luminous of all of the first-magnitude stars.
Measuring the distance of a star is called by astronomers find-
ing its parallax. Roughly speaking, parallax is the apparent
change of position that an object seems to make when viewed
from different points. If you hold a pencil out in front of you
about one foot and look at it with first one eye and then the
other, you will see that it seems to change its position relative to
any object back of it. If you hold the pencil farther away, you
will see that the change of position seems less, and if you place it
still farther away, there seems to be no change of position at all.
Then if you will move your head from side to side and thus
lengthen the line between the two points of observation, which
was at first only the distance between your eyes, the pencil will
have to be placed still farther away before it seems to remain
stationary when looked at from both points of view. The longer
the distance between the two points of observation, the farther
away the object observed will have to be to remain in appar-
ently the same place when viewed from each point. When math-
ematicians know the length of the base line (that is, the line
connecting the two points of observation), and can measure
the angle made by the meeting of the other two lines (that is,
the lines from the two points of observation to the object ob-
served) , they can tell how far away the object is,
When looked at in the ordinary way, a star never seems to
change its position in the heavens. Even if viewed from points
whose distance from each other is the whole diameter of the
earth, eight thousand miles, it shows no change of position.
86 The Friendly Stars
At first thought one would think that we could not find a line
longer than that from one side of the earth to the other. But
astronomers have found one in space. It is the diameter of the
earth's orbit, or the path over which the earth travels in its
yearly journey around the sun. This diameter is 186,000,000
miles long, or more than twenty-three thousand times as long
as the diameter of the earth. Observations of the stars whose dis-
tance is to be measured are made when we are at one point in
the earth's orbit, and then again six months later, when we are
at the opposite point, or 186,000,000 miles removed from the first.
A few stars change their apparent positions when thus observed
from the two ends of this great line; but the changes are still
very slight. By strict mathematical calculation we know, how-
ever, that any star showing a change of position of only one
second, the smallest subdivision of a circle, when viewed from
each end of a line 186,000,000 miles long, must be a little more
than nineteen trillions of miles from us. Thus far no star in
the heavens has been found to change its position this much; or,
as astronomers say, no star has yielded a parallax as large as one
second (1") . Consequently, as far as we know, there is no star
as near to us as nineteen trillions of miles. The largest parallax
that has been found is .75 of a second. Actually, a minimum of
three observations is needed to determine the parallax of a star.
The third observation enables the astronomer to distinguish be-
tween the apparent drift of the star across the sky caused by the
relative motion of star and sun and the shift caused by the
parallax.
The sun is ninety-three millions of miles from us, yet if we
were journeying in space, we might reach the sun and then go
two hundred thousand times farther away and still not come
near any fixed star. Indeed, we should have to go still eighty
thousand times the sun's distance from the earth, for a parallax
of ,75 of a second means a distance of seven trillions of miles
more than the nineteen trillions. In other words, the nearest
star that has been discovered is about twenty-six trillions of miles
away, which is equal to two hundred and eighty thousand times
the distance of the earth from the sun.
Other stars are many times farther away than this. Their dis-
tances in miles expressed in figures are not much easier to com-
prehend than infinity. Most astronomical numbers are too large
The Distances of the Stars 87
to comprehend and too cumbersome for easy use. For this rea-
son the distance of the earth from the sun (93,000,000 miles)
has been adopted as the astronomical unit, and in expressing
long distances we ordinarily say so many times the sun's distance.
But some of the stars are millions of times the sun's distance,
which still gives us an awkward lot of figures to deal with. As-
tronomers have, therefore, chosen another unit of length for ex-
pressing stellar distances. This unit is the distance over which
light passes in a year. We know that light travels at the rate of
186,300 miles in a second. This equals about six trillions of
miles in a year, or about sixty-three thousand times the sun's
distance. Therefore, for every six trillions of miles that a star is
distant we speak of it as one light year away. The nearest star,
then, is a little more than four and one-third light years away,
which means that its distance is more than four and one-third
times six trillions of miles.
The light that we see from the nearest fixed star left there
more than four years ago. From many stars we do not see it
for a hundred years, or for many hundreds of years. From some
of the faintest stars it may take light many thousands of years
to reach us. Streams of light are travelling towards us now that
set out on their journey long before Christ was born and have
not yet reached us. The stars from which they come might no
longer exist. The Pole Star, which we think is the most stable
thing in the universe, might be extinguished for nearly half a
century and we should still be ignorant of the fact; for the light
that we now see probably started on its journey to us almost
fifty years ago. And this though the velocity of light is so great
as to send it around the entire circumference of the earth (25,000
miles) more than seven times in a second. From the nearest fixed
star our sun, which gives us ninety billion times more light than
a first-magnitude star, would shine only as a star of the second
magnitude. Pluto, the farthermost planet of the solar system,
is about three billions of miles from the sun; yet between us
and the nearest fixed star we could line up several thousand such
solar systems just touching one another and still have some room
left over.
We think sound travels fast when we say that it goes at the
rate of one thousand and ninety feet per second. But if it were
possible for sound to travel to us from the nearest fixed star, it
88 The Friendly Stars
would, even at this rate of speed, spend three millions of years
on the journey through space. Fortunately sound is dependent
on our atmosphere for its motion and does not travel through
space as light does. If it did, we would probably have such a
mighty and continuous thunder that our ears would have to be
constructed very differently from what they are now to stand the
shock; for tremendous explosions and upheavals are going on all
the time among the stars, of which our sun is one.
Even though the sound waves from such disturbances do not
plague us, we have nonetheless become aware of the disturbances
because of the radio noise such disturbances produce. During
periods of intense sunspot activity, sensitive radio receivers pick
up a violent hissing noise that swishes on different frequencies
of radio waves. Many objects in the stellar system also send out
a hissing noise indicating the presence of great disturbances.
One of the chief sources of radio noise is the Crab Nebula, in
Taurus. This object is a planetary nebula. It actually represents
the remnants of a star, a supernova, that exploded in the year
1064. Ancient records show that a bright star appeared in this
position in that year.
Measurement of stellar parallaxes is one of the most delicate
of astronomical operations. In such observations allowance must
be made for errors of various kinds. Even personal peculiarities
must be taken into account; for, with the same honesty of pur-
pose and working with the same instruments, persons of differ-
ent temperaments will still see things a little differently. So in
the final allowance for probable error which follows any calcu-
lation of delicate problems in astronomy, the astronomer takes
his personal equation into consideration. But apart from this
element of uncertainty, it is still not all a plain case of making
and recording observations in seeking a parallax. Account must
be taken of refraction, which causes an apparent deviation from
the real position of an object; of the motion of the earth
through space, which does not stop for the making of any ob-
servations, however important; of nutation, which is a wob-
bling of the earth on its axis; of precession, which is another
motion of the earth; and of still other disturbing motions.
The determination of the distance of the stars is still of great
importance to astronomers. However, indirect methods of de-
termination are now being pursued more actively than the direct
The Distances of the Stars 89
method of determination. The indirect methods involve using
certain characteristics of the star to give an estimate of its true
luminosity. The spectrum of a star, for example, provides a good
measure of the surface brightness. The relative intensities of cer-
tain lines can indicate the pressures within the star's atmosphere
and enable the astronomer to estimate whether it is a large
bright star or a small faint one. Or, in the special case of certain
types of variable stars, the period of the light variation provides
a measure of the star's actual luminosity. In either case, when
we know the star's intrinsic brightness, and also the star's ap-
parent brightness, we can then simply calculate how far the star
must be from us in order to appear as bright as it does in the
sky.
As previously noted, the brightest stars tend to be the nearest
ones to us, but there are many exceptions to this rule. It is more
accurate to say that, of the naked-eye stars, the faintest ones are
farthest away. Alpha Centauri, the nearest star of all, is a bril-
liant first-magnitude star a little more than four light years away.
Procyon, another first-magnitude star, is something less than ten
light years away. Sirius, the brightest star in the heavens, is also
comparatively near, its light journey through space being a little
more than eight years (8.6) . On the other hand, the second near-
est star, usually called Barnard's star, is just a trifle brighter than
the tenth magnitude (9.7) at a distance of about six light years.
Canopus, the star next brightest to Sirius, takes about 100
years to send its light to us. Arcturus, one of the brightest stars
in the northern hemisphere, is 37 light years away. Spica is at a
distance of 260 light years and brilliant Rigel at the record dis-
tance of 1,300 light years.
So, while it may be true that on the average a large propor-
tion of the bright stars are nearer us than the faint ones, it does
not necessarily follow that because a star is brighter than others
it is, therefore, nearer, nor that any particular faint star is among
those that are farthest away. Brightness is one of the criteria of
nearness, but it is not always the determining one. The excep-
tions to this rule are due in a large part to the fact that stars
themselves have intrinsic brightnesses ranging over an enormous
number of magnitudes. There exist, in space, stars more than
10,000 times as bright as our sun. We also find stars 10,000 times
fainter than our sun. These extremely faint stars are tremen-
$0 The Friendly Stars
dously abundant, but we can see them in our telescopes only to
a relatively short distance.
Of the distances of the stars from each other we can have no
conception until we know their distance from us. Some of those
that appear to lie very dose together may only lie in nearly the
same line of sight and may really be separated from each other
by many times their distance from us. There is reason to think,
though, that many of the groups are not mere accidents of vision,
but that most of the stars composing them have some close con-
nection and are probably comparatively near each other. This is
indicated sometimes through spectrum analysis and sometimes
through telescopic observation. By the spectrum we learn that
the stars in certain groups are all in nearly the same stage of
development; and thus they seem to have had a common origin
and may be comparatively near each other. This is the case
with the stars of the Pleiades. By the telescope we learn that all
the stars in certain groups are moving through space in the same
direction; and thus they seem to have a common destination.
Five of the seven principal stars forming the Big Dipper com-
prise one of these moving groups. The first star in the bowl of
the dipper and the last star in the handle are not members. It
turns out that our sun actually lies within the confines of this
enormous moving duster, although it is not a member. Sirius,
Alpha Coronae Borealis, and Beta Aurigae are also members
of the Ursa Major duster.
The Pleiades and the Hyades are also examples of moving
dusters. The motion of the latter group is rather unusual, in
that the stars appear to converge toward a certain point in the
sky. The effect is one of perspective. All of the parallel tracks
in a railroad yard, for example, converge toward the same point
on the horizon. In the same way, these stars, moving parallel to
one another, converge to the same point, which is not far from
the red star Betelgeuse in Orion. Many of the bright stars in
the constellations of Scorpius and Centaurus belong to the same
moving duster. The beautiful duster that comprises the constel-
lation Coma Berenices is a naked-eye group. So, also, is the
faint naked-eye duster Praesepe, in Cancer.
XX
Double Stars
A GREAT many of the stars that we see as one with the
^ naked eye are, in reality, composed of two, sometimes of
three, and in a few cases of four or more stars. The reason that
we see them as a single star is, either that they are too close to-
gether to show any space between them at the enormous distance
they are from us, or that one of them is too faint to be visible
without a telescope. Castor is an example of the first case. The
two principal stars composing it are of the second and third
magnitudes, and either of them could be seen with the unaided
eye if they were not so near together. Their nearness, of course,
is only comparative. Hundreds of millions of miles divide them;
but their distance from us is so great as to make many hundreds
of millions of miles dwindle to a mere point. Incidentally, Cas-
tor is actually a multiple star, having, in addition to the princi-
pal pair, several fainter companions. Regulus is an example of
the second case. It has a companion star which is too faint to be
seen with the naked eye, and yet the distance between the two
stars is no less than that between some other stars that the eye
can easily separate because they can both be seen by the eye
alone.
Sometimes we loosely call a star double when we can really
see without a glass the two stars composing it. Epsilon Lyrae,
which we already know, is such a star. To many persons it seems
to be a single star; but a good eye will discover that it is two.
They are three minutes apart, and this is about the smallest
distance that the eye can discern among the stars. A telescope, in
turn, will resolve each of these stars into a dose double, so that
in reality Epsilon Lyrae is a double double system.
The star next to Aldebaran in the V-shaped figure of which
it is a part is also spoken of as a double star, though its two
91
$2 The Friendly Stars
components are as much as six minutes apart and can ordinarily
be seen with the unaided eye. There are many such double stars.
But astronomers do not call a star double unless a telescope is
required to separate the components of it, and even then they
reject all stars that do not lie nearly ten times nearer together
than the two principal stars of Epsilon Lyrae.
Sometimes two stars lie in such a position that they seem to
us to be almost touching each other, yet are in no way con-
nected and only happen to lie in the same line of vision, one
being enormously farther away than the other. Their appearance
as one is a mere matter of perspective. Such combinations of the
light of two stars are called optical doubles, and are of no spe-
cial importance as double stars in astronomical investigations
after it has been fully established that they have no physical
connection.
True double stars do not lie near each other by mere chance.
They are held together by physical bonds that keep them forever
revolving around each other, and their revolutions are what be-
tray to us the relationship of the stars taking part in the motion.
Sometimes it requires many years to determine whether there is a
physical connection or not. For even though stars may be mov-
ing at the rate of many miles a second, their distance from us
is so great that it takes a very long time for us to discover any
motion at all. Hence, a star that requires several hundred years to
complete its journey in its orbit would hardly reveal any per-
ceptible motion in the lifetime of one man. A convenience it
would indeed be to the modern astronomer if he could com-
mand the same consideration as the old historian Berosus says
was given to the antediluvians when God prolonged their days
to five or six hundred years in order to give them time to com-
plete astronomical observations. The brevity of life, however,
does not stay the inquiring mind. The work of investigation is
passed on from hand to hand with almost as much continuity
as if it were pursued by a single man.
Generally speaking, there is a real connection between two
stars when they remain in the same relation to each other dur-
ing a long series of years. For each star is in motion and has its
own, or what we call its "proper," motion in the sky. If its com-
panion has the same motion, and the two stars thus keep to-
gether, there is reason to suppose that they form part of the
Double Stars 93
same system. If they remain together and yet change their rela-
tive positions, we know that they are circling round each other
and are undoubtedly of one system. But sometimes in their
revolutions through their incredibly large orbits the two stars
are enormously farther apart at one point than at another and
may seem to be receding from each other. In such cases it re-
quires long years of observation to determine whether each is
going its own way and they will continue to recede, or whether
they are bound together by gravitation and will in time ap-
proach each other again.
Sirius and its companion are entirely inseparable at one
point in their circuit and at another can be separated by a large
telescope. But as their period of revolution is only about fifty
years, their relation was soon established after the smaller star
was once seen during one of its periods of greatest distance from
the principal component of the system.
Castor and its distant companion, on the other hand, can al-
ways be seen separately by the aid of the telescope. But it was
only after they had been known as a double star for more than
a hundred years that any physical association was suspected be-
tween them. It came about then by the accidental discovery that
while once the prolongation of the line joining Castor and Pol-
lux would run through Castor's companion, it was no longer so;
but that the companion had moved quite out of line with Castor
and Pollux, showing that the two stars must be in revolution.
The time necessary for a revolution of a companion of Castor
around its primary is slightly under 400 years.
Double stars that are not mere optical doubles, but are proved
to have some physical connection, and, hence to revolve around
some common center, are known as binary stars, or binary sys-
tems, and the stars composing such a double star are spoken of
as its components. Those that can be separated with the tele-
scope are called visual, or sometimes telescopic, binaries. But
there is a class of binaries that cannot be separated even with
the strongest telescope. Their double nature is made known
to us by means of the spectroscope, and they are called spectro-
scopic binaries. Their discovery is one of the most interesting
results of the use of the spectroscope in astronomy.
The displacement of certain lines in the spectrum of a star
enables astronomers to determine the swiftness and direction of
94 The Friendly Stars
its motion. In the case of a double star the components revolve
around each other, alternately approaching and receding from
us. The lines of their spectra indicate these motions and betray
the fact that they are circling around in an orbit, and are, hence,
double stars, since if they are revolving they must be revolving
around something. When the two stars are of the same class
spectroscopically, they will each have the same kind of spectrum
and the lines of their spectra will alternately appear double and
single, according as the stars are side by side to our view or in
the same line of sight from us. When the two stars composing
the binary are so different in their stage of development that one
is nearly dark, the lines of the spectrum of the bright component
will simply oscillate back and forth, for, of course, a star that
does not radiate light has no spectrum. Mizar is an example of
the first class and was the first star to be identified as of that
class, this occurring in 1889. Mizar was also the first star dis-
covered to be a double star. Spica is an example of the second
class, since its companion star is almost non-luminous and signals
its presence only by the wavering lines of Spica's spectrum.
Gapella is of a class between the two, where the spectra of both
components can be seen, though they may be of slightly different
spectral types.
Up to the middle of the seventeenth century such a thing as a
double star was unknown. In 1610 Galileo first used his telescope,
by which he discovered the moons of Jupiter. For forty years
after that the heavens were scanned with various telescopes more
or less rude in construction, but not once did it occur that a star
which looked single to the naked eye became known to be double
as viewed through a telescope. Finally, in 1650, Mizar was dis-
covered to be composed of two stars. The idea once entertained,
double stars became an object of special quest, and many others
were discovered in quick succession, among them Alpha Centauri
and the famous Theta Orionis, the star in the nebula in the
sword of Orion, which was discovered as early as 1689 to be not
only double, but quadruple. But no one dreamed that double
stars were anything more than optical doubles. It was supposed
that by mare chance both stars lay in the same line of vision from
us, against the same background of black space, but one of them
necessarily much farther away than the other.
More than a hundred years after the first double star was
Double Stars 95
discovered, and so recently as about the time of our Revolu-
tionary War, a systematic search for double stars was begun. In
less than two years thirty-three stars were added to the number
already known. The astronomer Herschel then set about making
a special study of double stars, in the hope that he might be
able to learn something about their distance. The idea that one
was far behind the other in our line of sight at least differen-
tiated them as to distance and suggested the thought that it
might be possible to discover some shifting of the nearer star in
its relation to the farther one. The unexpected happened again,
and a new scientific truth was discovered almost, as it seemed,
by accident. The stars were revolving around each other! An-
other of nature's secret doors had been burst open by the con-
tinuous pressure upon it of zealous, untiring workers while
chiselling away one fastening after another.
By 1802 it was proved beyond a doubt that many of the so-
called double stars were truly double twin suns swinging around
a common centre of gravity: millions of miles apart, no doubt;
but held by that mysterious force that keeps our own system
together, in bonds that can never be loosened.
When Sir Isaac Newton termed that force "universal gravita-
tion," stressing the fact that the force held everywhere in the
universe, he was indeed far-seeing. These double stars proved
beyond all question the universal character of the force that
causes a stone to fall to earth, the moon to revolve in its orbit,
or the planets to circle the sun. Here was implication that many
other systems like ours could exist in the universe: a vast central
orb holding smaller ones by invisible chains and swinging them
around as a boy sometimes swings a pot of burning coals sus-
pended upon a string.
Sometimes two fiery suns of almost equal size are circling
around each other. They may each be the center of a planetary
system and so far apart that they show as mere stars to each
other. That they are so far apart, we know in some cases; and we
even know that in some cases dark bodies are revolving around
them. We may more appropriately refer to these dark bodies as
unseen companions, because in most cases the bodies are not
completely dark. They are only relatively faint stars which might
actually be seen in a large telescope or photographed were it not
for the presence of the bright companion.
96 The Friendly Stars
Why may it not be that many others are thus far apart and
accompanied by dark bodies which we have as yet no means of
discovering? Scientists have even suggested that our sun may
have a far-distant companion. However, the evidence is decreas-
ing for the reality of a companion sun, but the possibility cannot
yet be completely ruled out.
As soon as the fact that there was a physical connection be-
tween the components of some of the double stars was established,
many workers began to devote themselves to the observation of
such stars, sorting out and discarding the mere optical doubles,
watching and recording the movements of those that proved to
be real binary systems, and discovering new ones all the time. For
more than a century the work was carried on by means of the
telescope, and more and more pairs came into view as larger
and larger telescopes came into use.
Astronomers have estimated that almost one-third of all the
stars in the sky are binaries. The high incidence of binary sys-
tems clearly indicates that the evolutionary process leading to
the formation of the double star is in no sense unusual. The in-
dication is that a single star, originally rapidly rotating, may un-
der certain circumstances split up into a double star into which
most of the rotational motion has gone into the orbital revolu-
tion of one star about the other. These findings, as well as the
discovery that binaries, too dose to be separated even with the
strongest telescope, could be recognized either through the spec-
troscope or by the light variation of the eclipsing binary, greatly
enlarged the field of investigation.
Nearly a hundred of the binary systems discovered have
proved to be multiple systems composed of anywhere from three
to seven stars. Castor is a well-known multiple system. Polaris is
a triple star, Mizar a quadruple, Theta Orionis divides into four
bright stars* and Epsilon Lyrae is composed of four. From the
frequency with which this happens, it is hardly surprising to find
almost any binary resolve itself on further observation into a
system of several stars. Many binaries that can be seen with a tele-
scope have been shown by the spectroscope to have both com-
ponents double, thus making a quadruple system.
Many orbits have been computed, showing periods of revolu-
tion from less than two days to more than a thousand years in
length. The far-distant visual couples swing slowly and majesti-
Double Stars 97
cally around their common center, while the close companions
whirl with almost unthinkable rapidity through their allotted
orbits, for the shorter the distance between two stars the greater
gravitational force they exert upon each other and the more
swiftly they compel each other to revolve.
The fastest revolving couples are, of course, spectroscopic bi-
naries, many of which are so close together as to be almost in
contact. In proportion to the number of each, the orbits of more
spectroscopic binaries have been determined than of the visual
systems; for telescopic doubles must be observed until it is shown
that they either are or are not in revolution, while spectroscopic
systems are discovered because they are in revolution.
The shortest periods among spectroscopic binaries are a few
hours; the shortest periods among visual binaries are a few years.
It is interesting to know that the longest period found that has
reasonable claims to accuracy is that of a fourth-magnitude star
in the region between Altair and the square of Pegasus. It is es-
timated to be nearly sixteen hundred years; but it will require
several hundred years of observation to fully verify this estimate.
The longest period that has been computed and fully authenti-
cated is about four hundred years, though much longer periods
are known to be approximately correct.
Multiple stars grade into more complex systems, like the Ursa
Major cluster, the Scorpius-Centaurus group, the Pleiades and
Hyades, or Praesepe. The delicate naked-eye cluster, Coma Bere-
nices, is another. In the last chapter we saw that such groups are
physically connected because the stars are moving parallel to
one another. The clusters hold their shape.
The discovery of binaries, or systems, of stars has a most im-
portant influence in the progress of astronomy. In establishing
the universality of the law of gravitation it opens the way to
knowledge of various sorts which would otherwise be unobtain-
able. When the distance of a pair of stars is known and the time
that they require to revolve about each other, we secure data
for determining the size of their orbit, their mass, their real
light-giving power, and their rate of speed. In addition to this,
if we learn from the spectroscope the chemical composition of
the stars, it would seem as if their whole story is nearly within
our grasp.
XXI
The Constellations
HP HERE is a general impression that knowing the stars means
knowing the constellations; and with this idea in their minds
many persons grow discouraged at the very outset in their en-
deavors to make some acquaintance with the stars. But the first
step toward knowing the constellations is a familiarity with the
individual stars. At first sight, most of the constellations do not
much resemble the thing for which they are named. Many of the
figures partially overlap each other. The tip of one of the horns
of Taurus is in Auriga; Andromeda and Pegasus depend upon
the same star to complete their outline; and in some other cases
a star was traditionally assigned to two constellations, or fami-
lies, so that it is difficult to tell of which one it is the step-child.
Astronomers have, in questionable cases, arbitrarily decided to
which star group a given star belongs so that the constellations
do have officially recognized boundaries.
To enjoy the constellations one must be satisfied not to expect
too much of them. The splendid ones that mark a certain section
of the skies to us, as well as the small and beautiful ones that re-
mind us by their presence that a certain season has arrived, yield
their fullest pleasure when we take them as we do our human
friends for what they give us, without any severe exactions as
to consistency or any desire to make them fit a preconceived
model. The tracing of the various figures represented by the con-
stellations was not the working out of an exact science, but it was
an aesthetic occupation, and the imagination must be used to
see, as the ancient star-gazers did, the heroes, kings, and queens,
and birds and dragons fixed on the purple walls of the sky.
It is not necessary that one should be able to trace all the con-
stellations in order to have a friendly and familiar acquaintance
with all the important naked-eye stars. Still one can hardly be
98
The Constellations 99
said to know the aspect of the heavens until he knows the prin-
cipal constellations the ones that took shape in the minds of the
shepherds, sailors, and other out-door people in the days when
imagination fashioned them and when scientific order was of less
import than it is to-day. These early forms include the twelve
constellations of the zodiac, for instance, which mark the path of
the sun and the moon and the planets across the heavens; the
conspicuously beautiful constellations, like Orion, Lyra, Leo,
Scorpius, and others; and the familiar ones forever circling
around the north pole, and always visible to us, like Draco,
Cassiopeia, and the two bears.
Moreover, however indifferent one may be to the science of
astronomy, an intelligent person can hardly fail to feel a little
uncomfortable when he has so large a body of natural beauty
hanging over him in full view half of his life and yet has no fa-
miliarity with it. It was some feeling of this kind, no doubt, that
led Thomas Carlyle to cry, "Why did not somebody teach me the
constellations and make me at home in the starry heavens,
which are always overhead, and which I don't half know to this
day?"
Of the ancient constellations there are about forty-eight. They
are all outlined by stars that can be seen with the naked eye and
are as open to our vision as the clouds, the trees, and the hills.
In them are contained all the brightest stars, and there is no
conspicuous part of the heavens that is not covered by them.
Once we are familiar with them, the whole sky becomes glorified
to us beyond Achilles' shield, which Hephaistos fashioned and
wrought thereon "the heavens, and the sea, and the unwearying
sun, and the moon waxing to the full, and the signs every one
wherewith the heavens are crowned, Pleiades, Hyades, and
Orion's might, and the Bear that men also call the Wain, her
that turneth in her place and watcheth Orion, and alone hath
no part in the baths of Ocean."
Today, astronomers recognize 88 constellations. These com-
prise the 48 original constellations recognized by the ancients,
with the exception of the Pleiades, which we now regard as be-
ing part of Taurus, and only an asterism. Also, astronomers have
carved the original large star group, Argo Navis, the great ship
in which Jason sailed to find the golden fleece, into four separate
groups, the sail, the stern, the keel, and the compass. There have
100 The Friendly Stars
been many new constellations added to the southern sky, regions
invisible in the latitudes where the ancient astronomers made
their observations. Also, the modern astronomers have straight-
ened out the once irregularly curved boundaries until they now
consist of arcs of circles.
Many of the modern constellations are of little interest or im-
portance, having been composed to provide a scientific genealogy
for the few inconspicuous stars occupying stray spots in the sky
not covered by the original constellations. The ancient astron-
omers referred to these as the "unformed stars." But, for astro-
nomical reference, it is often useful to have a map of the sky in
which no blank spots occur. Hence, though the areas are gen-
erally poor in stars and often of little interest, they are neces-
sary additions to the astronomer's system of mapping the sky.
Many of the newer constellations, especially those in the south,
do not follow the ancient pattern. They are named for such as-
tronomical or scientific instruments as the sextant, the octant, the
telescope, the dock, the graving tool, the microscope and others.
They are, in consequence, devoid of the romantic and historical
interest that the ancient constellations commanded. Fortunately,
the first astronomer to map the southern stars, Bayer, followed
the ancient tradition and introduced groups of particular beauty
and interest in the more brilliantly populated starry realms.
Fourteen of the principal constellations have already been de-
scribed more or less fully in the introduction to the first-magni-
tude stars. With these as connecting links we shall proceed to
identify and trace the other important constellations visible in
the northern latitudes.
XXII
The Little Bear and Polaris
FIVE major constellations are always above the horizon in our
latitudes: Ursa Minor, Ursa Major, Cassiopeia, Cepheus, and
Draco. We can see them on any clear night from sunset to dawn.
They are all in the north and revolve slowly in a small circle
around the north pole once every twenty-four hours. In one
sense the most important of these six constellations is Ursa
Minor, or the Little Bear. The reason of its importance is that
the north pole lies within its boundaries.
The north pole is nothing more than the point where the
imaginary polar axis of the earth would touch the sky if it
were extended that far. But since the earth revolves on its axis,
the entire heavens seem to us to revolve around its extension; so
the north pole is to our view the center of the universe and the
most important point in the skies.
Of all the stars that can be seen by the naked eye the one
nearest to the north pole is Polaris, or Alpha Ursae Minoris. It
is called the Pole Star, or the North Star, and is ordinarily re-
garded as marking the exact point of the north pole. It is, in
truth, about one degree from the polar point and revolves
around it each 24 hours in a little circle two degrees in diam-
eter. A diameter of two degrees is nearly four times the apparent
diameter of the moon, which is only a little more than half a
degree. But the moon, by reason of its brilliancy, seems to cover
more space on the sky than it really does, so we must make allow-
ance for that fact in such a comparison.
To find the exact location of the pole, draw a line from Polaris
to Mizar, the middle star in the handle of the Great Dipper.
Mizar is on the other side of the pole from Polaris and almost
exactly opposite; and the line will pass through the pole, which
lies about one degree from Polaris.
101
102 The Friendly Stars
Within the little cirde that Polaris makes around the pole are
many stars that are not visible to the naked eye. As many as
eighty have been seen through the telescope, while as many as
two hundred have been seen on the photographic plates.
Owing to what is known as the precession of the equinoxes,
the pole does not always point to the same spot in the sky. It
describes a little circle of its own once in every twenty-five thous-
and years, and as it journeys it confers the distinction of being
the Pole Star upon several different stars. In about two hundred
years from now it will approach our present North Star, Polaris,
to within a little less than half a degree. The circle that Polaris
will then make around the pole will have a diameter of about
fifty-three minutes, which is slightly less than twice the diameter
of the moon. After that, the pole will begin to move away from
Polaris* and in about twelve thousand years will be within
five degrees of the beautiful Vega, and she will be our Pole Star
for the next three thousand years. Then the pole will slowly
recede from Vega, and in another twelve thousand years Polaris
will again become the Pole Star. So, in spite of all these changes,
each generation during these thousands of years will have its
Pole Star. For the change takes place so gradually that a single
generation is not conscious of it. The change has been marked,
however, over historical time. Some 2,000 years ago the "guard
stars," Beta and Gamma Ursae Minoris, were nearer the celestial
poles than was the star that we call Polaris. Hence it was cus-
tomary for the early navigators to steer by the guard stars rather
than by Alpha Ursae Minoris, Around 3,000 B.C., Alpha Dra-
conis was the pole star.
Polaris is the brightest star in the constellation of Ursa Minor,
or the Little Bear. Its Greek letter name is Alpha Ursae Minoris.
It was also called in former times Cynosura, meaning the end of
the dog's tail. It is at the end of the tail of the Little Bear: and
tfaane is some reason to think that the Little Bear was once
thought to be a dog instead of a bear. Our word "cynosure" gets
its meaning from Polaris, which is the center of attraction in the
heavens,
In the Little Bear, as in the Great Bear, the distinctive feature
of the constellation is the Dipper. It is formed of seven stars and
somewhat resembles the Great Dipper: but its handle is curved
The Little Bear and Polaris
103
f70
THE LITTLE DIPPER
towards, rather than away from, the bowl, which gives it some-
thing more the appearance of a saucepan than of a dipper.
The only other stars of any importance in the constellation
are the two outer stars of the bowl of the Dipper. The brighter
one is a second-magnitude star, Beta Ursae Minoris, sometimes
called Kochab. The other is Gamma Ursae Minoris, a third-
magnitude star. They correspond in position to the pointers
in the Great Dipper, and are sometimes called the "guardians
of the pole."
XXIII
The Great Bear and the Seven Stars of
The Dipper
T TNLIKE the Little Bear, the Great Bear can be traced in the
heavens with reasonable accuracy. It looks rather more like
a rodent than a bear, and its long tail seems somewhat out of
place. Still one can distinctly follow the outlines of a clumsily
shaped four-legged animal, which, perhaps, is as appropriately
called a bear as anything else. It is rather surprising, however,
that many ancient peoples in widely separated continents have
referred to this constellation as a bear.
The most conspicuous part of the constellation is the Great
Dipper, The handle of the Dipper is the tail of the Bear, and
the four stars forming the bowl lie in the hind part of the body.
The tip of the Bear's nose is marked by a star lying about twenty-
five degrees from the root of the tail, and a line from the nose
through the two stars forming the top of the bowl of the Dipper
marks the back of the Bear. Its right fore-foot is indicated by two
stars about fifteen degrees south of its nose. The stars connecting
this foot with the body show a prancing, double-jointed sort of
a leg. Similar pairs of stars indicate the position of the other
three feet, which can be appropriately connected with the body
without much trouble, the whole forming an animal so huge that
it might well give over its watch on Orion, since even so mighty
a hunter as he would scarcely attack it.
Ursa Major is a beautiful constellation and would be remark-
able even if its only distinction were that of including the seven
bright stars of the dipper. These stars are well worth a closer
acquaintance because of their many points of individual interest
and beauty as well as their special interest as a group. With the
exception of Orion, there is no other constellation with so many
104
The Seven Stars of the Dipper 105
bright stars in so dose a group. Alioth, the third star from the
end of the handle, is the brightest of them, and barely escapes
being a first-magnitude star. All the others are of the second
THE SEVEN STARS OF THE BIG DIPPER
magnitude except Megrez, which lies at the point where the
handle joins the bowl of the Dipper. This is a third-magnitude
star.
Alioth is five and a half degrees from Megrez, or Delta, the
faintest star of the seven, and is four and a half degrees from
Zeta, or Mizar. The name AJjoth means the "tail sheep/'
Alkaid, the star at the end of the handle of the Dipper, is the
third in order of brightness in the group, though no longer ago
than 1847 it was said by Herschel to be the brightest. The differ-
ence in brilliancy between Alkaid and Alioth is hardly discernible
by the ordinary eye. Alkaid is a white star and is approaching us
at the rate of about seven miles a second. Its name means "the
chief." The star is frequently called Benetnasch. It is seven
degrees from Mizar, the star next to it in the handle of the
Dipper, and twenty-six from Dubhe.
Dubhe, or Alpha Ursae Majoris, is the pointer nearest the pole
The name means the "she-bear." Dubhe lies in the back of the
Great Bear, ten degrees from the star that begins the tail of the
Bear; It is the second in order of brightness in the constellation.
Dubhe is yellowish in color and shows some similarity to
Capella. It is a double star. Its smaller companion is about three
magnitudes fainter than the larger star, being of the fifth magni-
106 The Friendly Stars
tude. This makes a great difference in the brilliancy of the two
stars, the brighter one being sixteen times brighter than the
other. Dubhe is a little more than twenty-eight degrees from
Polaris; ten degrees from Megrez, the other star at the top of
the bowl of the Dipper; twenty-six degrees from Alcaid, the star
at the end of the handle, and a trifle over five degrees from the
other pointer. It is approaching us at the rate of five miles a
second.
The other pointer is Merak, or Beta Ursae Majoris. It is fifth
in point of brightness in the constellation, its magnitude being
2.37, and is a very beautiful white star' with a greenish tinge. It
is approaching us at the rate of about seven miles a second.
From Phecda, or Gamma Ursae Majoris, the other star at the
bottom of the bowl, it is four and a half degrees to Megrez, or
Delta Ursae Majoris, the faintest star of the seven bright ones in
the Dipper. Its magnitude is 3.30. Megrez is also whitish; like
Phecda, it is slightly tinged with yellow. Its name means "the
root of the tail," which describes its situation in the Great Bear.
It is the star that joins the handle to the bowl in the Dipper. It
is five and a half degrees from Alioth, the brightest of the seven,
and is thirty-two and a quarter degrees from the pole.
The most variously interesting of all the stars of the Great
Dipper is Mizar, or Zeta Ursae Majoris/ the star next to the one
at the end of the handle. It is fourth in order of brightness
among the seven, its magnitude being 2.05, almost an exact
second-magnitude star. The light from Mizar takes about 80
years to reach the earth.
Mizar can always be known by its having a tiny companion so
near it as to be sometimes not easy to see. Its name, Alcor, means
"the near one." It was formerly known as "the test," because it
was supposed to test the eyesight to see it. It is really not so
difficult to see, however, for it is only a fourth-magnitude star
and is separated from Mizar a distance equal to almost one-third
of the apparent diameter of the moon. The greater light of
Mizar is what makes it seem so obscure. When Alcor is once
known, it never fails to attract, for it is a peculiarly beautiful
little star, very white and very piercing in its brightness. We have
already noted that ail of the Dipper stars with the exception of
Dubhe and Alkaid are members of a giant moving cluster. Alcor
The Seven Stars of the Dipper 107
is also a member of this group. Thus Mizar and Alcor are not too
distant from one another.
But Mizar has other stars nearer it than Alcor. It is the center
of its own great system of stars. It has the distinction of being the
first double star discovered by the telescope, a discovery made
as long ago as 1650. When the spectroscope came into use, Mizar
was again the first to open up a new line of discovery, being
the first star discovered by the spectroscope to be a binary. The
brighter of the two stars into which it was separated by the tele-
scope was shown by the spectroscope to be also double. So the
star as we see it is really three stars all united into one system.
The pair of stars that require a spectroscope to separate them
revolve around each other in a little more than twenty days and
radiate about forty times as much light as the sun.
In England the Dipper is often called the Plough and some-
times Charles's Wain, or simply the Wagon. As noted earlier,
all of its stars except Dubhe and Alkaid are moving through
space in the same direction and at about the same rate of
speed, which indicates that they may all be of one system,
or, at least, of a common origin, and thus be associated in
reality as well as to our view. Since Dubhe and Alkaid do not
belong to the cluster and are moving through space in a very
different direction, the dipper will become somewhat misshapen
in the course of centuries. In about 50,000 years it will appear
more like a lopsided steamer chair.
XXIV
Cassiopeia, Cepheus, and the Dragon
/CASSIOPEIA lies on the other side of the pole from Ursa
Major and almost directly opposite the Dipper. Its chief
naked-eye stars, seven in number, form a figure somewhat re-
sembling a chair in shape. They are nearly as conspicuous
among the circumpolar stars as the Dipper and are about the
same distance from the pole.
On account of the faintness of the little star Kappa (*), on the
front edge of the seat of the chair, some persons leave it out
of consideration and fancy the remaining stars outline a some-
what distorted "W."
Gamma (y) Cassiopeia? is at present the brightest star in the
constellation, and is of the second magnitude. Its light varies
irregularly, and for a short time it once rivalled Deneb in
brightness. Alpha is a shade less bright, and Beta is also of the
second magnitude. Delta (8), the first star in the back of the
chair, is dose to the third magnitude in brightness. Epsilon ( c ) ,
at the top of the back, is of the third magnitude; and Kappa,
already referred to as the little star on the front edge of the seat,
is a fourth magnitude star. Eta (if), half-way between Alpha and
Gamma, is an interesting binary, or double star. The two stars
composing it complete a revolution around each other every
five hundred years, and are comparatively near to us, being
only about eighteen light years away.
Only two stars in Cassiopeia have individual names. Alpha is
sometimes known as Schedar, and Beta was formerly called Caph.
Polaris is just about half-way between Caph and Megrez, the star
that joins the handle to the bowl of the Dipper, and is on the
same side of the pole with Caph.
108
Cassiopeia, Cepheus, and the Dragon
109
+60*
CEPHEUS
Next to Cassiopeia is Cepheus, the king, her husband. He
stands with one foot on Polaris and his head reaching to Andro-
meda. The constellation has only one second-magnitude star,
Alpha, which was formerly called Alderamin, meaning "the
arm." This star and Beta, a rather bright third-magnitude star
lying eight degrees nearer the pole than Alpha, point almost as
directly to Polaris as the well-known pointers. They are a little
nearer the pole than the pointers and are about three degrees
farther apart.
When Cassiopeia is east of the pole Cepheus is just above her.
When she is above the pole, he is west of her; and when she is
below it, he is just east of her.
THE DRAGON
The only other important constellation among those around
the north pole is Draco, or the Dragon. It is supposed to repre-
sent, and does somewhat suggest, a great dragon that winds in
110 The Friendly Stars
and out among the circumpolar stars in graceful serpent-like
convolutions. It is the Dragon on which the giant Hercules rests
one foot. Its head is marked by a four-sided figure a short dis-
tance northwest of Vega, containing two bright and two faint
stars. Since the head of Draco never sets, it is interesting to watch
it when Vega is below the horizon, and one sometimes has a
feeling that by a good big stretch on the tip of his toes he could
see the bright Vega just below the shining eyes of the Dragon.
The rest of the constellation is outlined by a number of faint
stars. It runs a short distance towards Cygnus, and then with
some well-marked undulations it runs up towards Cepheus until
it is between Cepheus and the Little Dipper. There it turns,
makes a sweep around the Little Dipper, and, running between
it and Ursa Major, ends just above the bowl of the Great Dipper.
The two brightest stars in Draco are the ones in the head. The
brightest is the one nearest Vega, which is Gamma ( y ) Draconis,
sometimes called Etamin. The other is Beta (0) , with the
individual name of Alwaid. Gamma is a second-magnitude star,
and Beta is of the third magnitude. Gamma is a beautiful orange-
colored star and is about 80 light years away from the earth.
A small star near the tail of the Dragon, lying half-way be-
tween Mizar, of the Great Dipper, and the lower star in the bowl
of the Little Dipper, is noted as having been the Pole Star four
thousand years ago. Its name is Thuban, and it is the Alpha of
the constellation, though Draco now contains a number of other
stars that are brighter.
XXV
From the Hunting-Dogs to the Arrow
CANES VENATICI
JUST under the handle of the Great Dipper is a collection of
J faint stars called Canes Venatici, or the Hunting-Dogs. The
only naked-eye star of any importance in it is Alpha, commonly
called Cor CarolL It gets its name from a modern attempt to
make a constellation in honor of King Charles IL of England.
The name means "the heart of Charles/' When the handle of the
Great Dipper is turned towards the west, Cor Caroli hangs under
it in a very conspicuous position and is a star that one would
naturally notice and inquire about. It forms a triangle with
Arcturus and Alkaid, or Benetnasch, the star at the end of the
handle of the Dipper. It is one of the brightest of the third-
magnitude stars. It is also a double star, with a companion of
about the fifth magnitude; but the two are too close together to
be separated by the naked eye.
BOOTES
Canes Venatici is a sort of connecting-link between the strict
circumpolar constellations and those that make a somewhat
larger circle around the pole and are not visible all the time.
Perhaps the easiest way to find them is to look for them one by
one as they follow each other up from the eastern horizon. Canes
Venatici is supposed to represent two hunting-dogs on the trail
of the Great Bear, and they are naturally followed by the hunter,
or the bear-driver, Bootes, which rises next The constellation is
represented by a kite-shaped figure that rises about eight o'clock
early in March. One can find it easily by the great star Arcturus,
ill
112 The Friendly Stars
with which we are already familiar, and which lies in the knee
of the hunter. It is a very pretty constellation and of some
astronomical interest, but it is not remarkable to the ordinary
view except for its one brilliant star.
CORONA BOREALIS
Corona Borealis, or the Northern Crown, is a semicircle of
stars that rises just east of the northern part of Bootes. Its chief
star Alphecca (Alpha Coronae) comes into view just an hour
and a quarter later than Arcturus. It is of the second magnitude,
though much fainter than the brightest second-magnitude stars.
The constellation as a whole is a rather brilliant one, notwith-
standing that it has no star brighter than the fourth magnitude
except Alphecca. There are seven principal ones, and most of
them are of the white, twinkling kind, so that the crown is full-
jewelled. The entire constellation is only about fifteen degrees
across.
HERCULES
Next after Corona rises Hercules, one of the large constella-
tions. It begins just south of the head of Draco and runs to
within four degrees of the equator. The chief stars composing it
delineate a giant upside down, as shown in the diagram on the
opposite page.
This constellation represents Hercules kneeling and with one
foot on the head of the dragon, Draco. Many authors have
placed a dub in his hand, but the concept of a kneeling giant
carrying a club seems somewhat out of place. The reviser of this
book (DHM 1963) has made a special study of the origin of this
constellation. He believes that he has found the answer in
diagrams and pictures of Hercules drawn on ancient pottery of
Greece. Apparently the proper representation is that Hercules
holds in his outstretched hand a bow. He is kneeling to gain
stability. He has just shot the arrow, the constellation Sagitta,
which is flying towards two birds, Cygnus and Aquila. The
pottery fragment dearly showed the kneeling Hercules holding
the bow, the flying arrow, and the Stymphalian birds as the
From the Hunting-Dogs to the Arrow
113
+40
+30
+20
target. Many of the older sky maps represented Lyra also as a
bird, a vulture. An alternative name for Lyra m these older
maps was Vultur.
In the legends of Hercules we find that one of the tasks he
was assigned during the performance of his twelve labors was
the shooting of the birds that haunted the marsh Stymphalis.
These birds were fierce, brazen-clawed and brazen-beaked. It
seems entirely fitting that the constellation should depict the
114 The Friendly Stars
famous giant performing one of his twelve great labors.
Hercules has no star as bright as the second magnitude, but
has many of the third and fourth magnitudes, and has also
several double stars. The constellation is directly north of
Scorpius.
LYRA AND CYGNUS
Lyra, or the Lyre, is the next constellation eastward from the
northern part of Hercules. It contains the brilliant Vega, and its
form has already been described. In addition to Vega, it has a
famous star, Epsilon ( ) ; a variable star, Beta (), whose chang-
ing light results from the eclipses of two stars revolving around
one another; and a rare nebula, known as the Ring Nebula, on
account of its shape. Epsilon can be divided into two stars by
a sharp eye, and to try to see them is an interesting exercise.
Each of the two is again double. Vega and Epsilon, with Zeta
(), the star nearest to Vega in the parallelogram described on
page 27, form an equilateral triangle each side of which is two
degrees in length. This will enable one to find Epsilon.
According to legend, Lyra represents the invention of the
musical instrument by the god, Mercury. He found a tortoise
shell and strung strings across it, finding that the plucking of
the strings gave out sweet music One is not quite sure whether
Lyra was supposed to represent the musical instrument itself or
the tortoise whose shell became part of the instrument. Most of
the early maps show it as a stringed instrument, however. But the
representations consistently add wings and a bird's head to
the instrument itself. This probably comes about because of con-
fused mythology. We have already noted that Lyra sometimes
has been referred to as Vultur, the vulture. Hence the bird's
head may very well represent the head of the vulture. On the
other hand, a badly drawn tortoise head might readily have been
mistaken for the head of a bird in some artistic rendition of the
constellation. So the beginnings of this beautiful group are lost in
prehistory.
Gygnus, the Swan, is the constellation that holds Deneb. In
its rising, Cygnus follows Lyra, and has been fully described in
the chapter on Deneb.
From the Hunting Dogs to the Arrow 115
AQUILA, THE DOLPHIN, AND SAGITTA
In Aquila we recognize the bright Altair, which, with its two
companions, already known to us, serves to indicate the constel-
lation. Exactly eight degrees below Altair when it is on the
meridian is a conspicuously variable star (Eta Aquilae), which
changes from the third to the fifth magnitude every seven days.
Its changes are well-marked to the unassisted eye and make it an
interesting object to follow from night to night. It is best seen
in the early autumn, when Aquila is on the meridian during
the first part of the evening. The two companions of Altair are
Beta and Gamma Aquilae. Beta is south of Altair, and Gamma is
north of it. The line joining the three stars is just five degrees in
length. Aquila is supposed to represent an eagle flying towards
the east and across th Milky Way.
The Dolphin, or Job's Coffin, in the shape of a diamond, is
just east of Aquila and a little farther north than Altair. Three
of the stars composing the diamond are a little variable; one of
them is a double star, and another is a spectroscopic binary,
which is also suspected of being a triple star.
Near the Dolphin is an equally miniature constellation,
Equuleus, the small horse. This constellation lies in the area of
the sky devoted to aquatic creatures. The reviser of this book,
therefore, prefers to regard Equuleus as a Sea Horse rather than
an ordinary horse. This makes it an appropriate companion to
the nearby Dolphin.
Sagitta, or the Arrow, lies in the Milky Way, north of Aquila
and south of Cygnus. It is composed of five stars so arranged as
to suggest an arrow pointing towards the east. Though a very
small constellation, it is pretty and easily found. As previously
noted, Sagitta naturally fills the position of the arrow shot from
the bow of Hercules.
XXVI
From the Winged Horse to the Bull
TP HE next constellation of any Importance that we may expect
to see in the east is Pegasus. Nearly three hours after Altair is
in view, the principal stars of Pegasus are seen coming up over
the horizon a little north of east. It is a large constellation com-
posed in the main of small stars. The chief figure consists of a
large square called "the square of Pegasus." Each side is nearly
eighteen degrees long, and the four stars composing it are suf-
ficiently bright to make the square a significant figure in the sky.
On the northeastern corner of the square is a small triangle
which serves as an identifying mark. The star on this corner of
the square is called Scheat. It is Beta Pegasi and the third star in
order of brightness in the constellation. Alpha Pegasi (sometimes
called Markab, the "Saddle") is on the southeastern corner of
the square. Alpha is slightly brighter than Beta. Algenib, or
Gamma Pegasi, marks the other lower or southwestern corner.
This star is somewhat less bright than Beta. The star in the
fourth corner of the square, which is the brightest of them all,
really belongs to Andromeda, though, in effect, two constella-
tions share the star. It was formerly Alpha Andromedae and also
Delta Pegasi: but it is now not included in Pegasus, although it
is dearly necessary to complete the asterism called the Square of
Pegasus, Its individual name is Alpheratz. The brightest star
belonging to the Pegasus family is Enif, or Epsilon Pegasi. It
lies about ten degrees east of the little diamond of the Dolphin.
Pegasus is supposed to represent the winged horse, the favorite
of the Muses. But as to its position in the sky authorities differ.
Some depict the horse as rising upside down, with his fore-feet
pawing the air up towards Cygnus and the top of his head resting
on the urn of Aquarius, But if one adopts that position, Pegasus
never entirely rights himself in his journey across the skies, as
116
From the Winged Horse to the Bull 117
some of the figures of other constellations do. In this representa-
tion, ever on his back, he goes pawing across the heavens and
down "into the depths of the ocean" symbolic, perhaps, of the
condition ascribed to those who ride him.
However, there is an entirely different picture, one more con-
sistent with the mythology of the group. In this representation
the square no longer outlines the body but the wings. The entire
figure is reversed, top for bottom. The important effect of this
inversion is that the front feet of the winged horse now rest
directly on Aquarius. The legend is that the horse struck the
rocks with his forefeet, causing a fountain to flow from them,
the fountain of Hippocrene. The reviser of this book prefers
this second representation.
ANDROMEDA
The constellation Andromeda is supposed to represent a beau-
tiful lady chained to the rocks. She was the daughter of Queen
Cassiopeia and King Cepheus, who are near her in the skies and
have been described, and she was brought to this situation be-
cause her mother boasted too much of her beauty.
The constellation is more than thirty degrees in length and is
outlined by a row of four bright stars, beginning with the one
in the corner of the square of Pegasus and running northeast
across the heavens in a slightly curved and easily traced line
under Cassiopeia. Andromeda and the square of Pegasus are
shown in the illustration, together with the "segment of Perseus,"
which lies next to Andromeda.
The main stars in the two constellations are thought to sug-
gest an immense dipper; but for that matter one can find a
whole tinshop of dippers in the sky if his mind runs that way
and he is willing to admit a variety of styles in this useful
utensil.
Andromeda rises cradled on the rock to which she is bound,
her head lifted gently into view by the great square of Pegasus,
on which it rests, and her feet, very properly, coming up last.
But she sets in a most undignified fashion, drawn down head first
by the flying Pegasus, her feet waving above the horizon after
the rest of her is out of sight. The four chief stars forming the
118
The Friendly Stars
From the Winged Horse to the Bull 119
curved line are Alpheratz, or Alpha Andromedae, which marks
the head; Delta, lying in the shoulder, from which an arm is
outstretched towards the north; Beta, or Mirach, marking the
girdle; and Gamma, or Almach, indicating the foot. They are all
second-magnitude stars except Delta, which is of the third magni-
tude. Almach is a noted triple star which can be separated by
the telescope. The components are orange, emerald, and blue.
A short distance north of Beta is the famous Andromeda
Nebula, the brightest nebula in the entire sky. To the naked
eye it appears as a fuzzy star. A binocular, however, or a
small telescope will show it as an oval patch of haze. This
object, M31 and its faint companion M32, are galaxies, Milky
Way systems like our own. The larger contains perhaps a hun-
dred billion stars, revolving in a sort of stellar pinwheel. Light
from the Andromeda Nebula takes about one and a half million
years to reach us. Large telescopes break the structure up into
separate stars, though the hazy background of light comes from
the billions of stars too faint to be seen individually.
The Andromeda Nebula has one other distinction. Since you
can see it with the unaided eye, it is undoubtedly the most
distant object that anyone can see without telescopic aid. The
eye, however, even with the help of the largest telescope, does
not show the true spiral structure and individual details. It
takes photography to reveal the beauties of this nebula, which
is the nearest example of billions of other spiral galaxies, indi-
vidual clouds of stars that lie, here and there, like oases in the
empty universe of space. In the southern sky appear two nearer
galaxies, irregular in shape, the large and the small Magellanic
Clouds. These two galaxies are about 100,000 light years distant.
PERSEUS
The hero that rescued Andromeda from her woeful plight was
Perseus, and he also is enshrined in a constellation that adorns
the sky in the region a little north of Andromeda. Perseus lies
in a very brilliant part of the Milky Way and is a beautiful
constellation. The principal figure in it is a curved line of stars
called the "segment of Perseus," running from Cassiopeia towards
120 The Friendly Stars
Capella. Near the center of the segment is Mirfak, or Alpha
Persei, a bright second-magnitude star, the brightest in the con-
stellation.
The most noted star in Perseus is Beta, or Algol. It lies a little
southeast of Mirfak and forms a triangle with it and Almach, the
star in the foot of Andromeda. Algol varies in brightness from
second to third magnitude once in about every three days (2 days,
20 hours, 48 minutes, and 55 seconds) .
The name Algol signifies "the Ghoul." Indeed, the original
representation of Perseus depicts him as holding in his hand the
severed head of the Gorgon Medusa, the sight of which was
supposed to turn a person into stone. It is doubtful indeed that
the star received its name from the peculiar variation. The anci-
ents were probably unaware of the "winking" that seemed to
lend to the star a sort of demoniac quality.
Since Algol varies at such short intervals and so markedly, it
has long been an object of interest even to the naked-eye observer.
The mystery of its changes has been made clear by the spectro-
scope, and it is now known to be a spectroscopic binary with an
invisible companion that eclipses it about once in three days.
The eclipse lasts about eighteen minutes, and for that length of
time it is a faint third-magnitude star. Then it regains its bright-
ness and remains a second-magnitude star until the next eclipse.
Algol is interesting to observers in the latitude of New York
City a$ being the only star as bright as the second magnitude that
comes very near the zenith, or the point directly over our heads,
on its course across the heavens. When on the meridian it is
only about one-tenth of a degree from our zenith. Algol rises
about an hour earlier than Capella. Perseus has two very beauti-
ful star dusters which make a splendid display with the aid of
ordinary opera-glasses.
AURIGA
Auriga rises next after Perseus in the northeast. It is the
constellation that contains the charming Capella, which is, of
course, its brightest and most important star. Its five brightest
From the Winged Horse to the Bull 121
stars outline a five-sided figure that somewhat resembles a
shield. Aside from Capella, the constellation has only one star as
bright as the second magnitude. This is Beta Aurigae, or Men-
kalinan. The other three stars of the pentagon are of the third
magnitude.
The mythological significance of Auriga is somewhat confused.
Many of the atlases depict Auriga as a goatherd holding a small
she-goat in his arms. Indeed, the term "Capella" does mean the
"goat star." There is the possibility, however, that the goat star
received its designation because its appearance in the sky pre-
saged the rising of the constellation of Capricornus, the Sea
Goat. Capricornus was supposed to bring torrential rains and
hence the recognition of its rising was important to the ancients.
On the other hand, there, is an entirely different potential
representation of Auriga. Many authorities have depicted Auriga
as the Charioteer. The question is, then, who is riding in this
chariot and why? Resolution of this enigma has been a particu-
larly interesting problem to the reviser of this book. The answer
seems to be relatively simple. The charioteer is none other than
Neptune or Poseidon, god of the sea. Whenever the sea god rose
from the waves and ventured forth on land he was supposed to
ride in a chariot drawn by sea horses. Or, in other representa-
tions, this chariot was a sort of sea chariot drawn by sea horses
whose reins Neptune held in his hands. In the vicinity of ancient
Rome, many fountains or mosaics depict Neptune rising from
the sea, riding in the chariot and driving the sea horses before
him.
How appropriate it is that Neptune should be in this partic-
ular place in the sky. For indeed it was Neptune who formed the
base of the entire legend linking the constellations of Cassiopeia,
Andromeda (daughter of Cassiopeia), Perseus, and Cetus. It
was Cassiopeia who offended the sea nymphs by boasting that
she was fairer than they. Thus she was banished to the sky, to
swing around the pole, half time head downward. And, as
additional punishment, Neptune chained her daughter to a
rock and sent the Sea Beast, Cetus, to ravage the coast and devour
the maiden. It was Perseus, riding in on Pegasus the winged
horse, who rescued the maiden. The lost meaning of the constel-
lation of Auriga is thus reconstructed. The five-sided figure may
122 The Friendly Stars
well be the chariot on which Neptune is riding, surveying the
havoc his orders produced.
TRIANGULUM
Just below, or east, of Andromeda is a pretty little constel-
lation called Triangulum, or the Triangle. There are only five
stars in it, and the brightest one is only of the third magnitude.
Two others are of the fourth, and two of the fifth magnitude. It
rises about half an hour after Andromeda.
ARIES
Next east of Triangulum is Aries, a small but important constel-
lation. Its importance consists in its being one of the constella-
tions of the Zodiac, which mark the path of the sun. The sun
passes through it from April 15th to May 13th; so that six
months later it is exactly opposite the sun in the skies and rises
just as the sun sets. It is the first sign of the Zodiac; but owing to
the precession of the equinoxes the signs of the Zodiac do not now
correspond with the constellations of the same name. From the
middle of March to the middle of April, when the sun is in the
sign of Aries, it is in the constellation Pisces; and when it is
really in the constellation Aries, it is said to be in the sign
Taurus.
The chief stars of Aries form a triangle in size about like
Triangulum, and the two constellations are sometimes mistaken
for each other by observers not entirely familiar with these con-
stellations. It should be remembered that Triangulum rises first
and is about half-way between Aries and Andromeda, and that
the apexes of the two triangles point in different directions.
The chief star of Aries is HamaL It rises about three-quarters
of an hour after Algol and about fifteen minutes before Capella,
It is the brightest star in the constellation and is of the second
magnitude. The next brightest is Beta Arietis, or Sheratan. It is
about oneialf a magnitude less bright than Hamal and is about
three degrees below, or east of, it in the sky. The two stars mark
the base of the two horns of Aries, or the Ram.
From the Winged Horse to the Bull 123
TAURUS
Taurus is the splendid constellation in which Aldebaran lies,
and can always be recognized by that bright star. It is the third
constellation and second sign of the Zodiac. The sun passes
through it from May 13th to June 18th, so it may be seen rising
as the sun sets six months later from the middle of November
to the middle of December.
Taurus contains the cluster of the Hyades, which are supposed
to rule over wet weather and are sometimes referred to in poetry
as the "moist Hyades." Aldebaran, as we have seen, is one of this
cluster. The cluster outlines the face of the Bull. Above it are
the Pleiades, which lie in the Bull's shoulder. The tips of the
horns are indicated by two stars near Auriga. One of these stars
is shared by both constellations to complete the legendary out-
lines. However, it officially belongs to Auriga*
The Bull rises backward, with its head lowered under the
threatening arm of Orion, and it backs all the way across the
heavens, going down without having made the terrible onset
that it all the time promises.
XXVII
The Mystery of the Pleiades
F all the groups of stars in the heavens none has excited so
universal and so romantic an interest as the Pleiades. The
magic of their quivering, misty light has always made a strong
appeal to men of imagination. Minstrels and poets of the early
days sang of their bewitchment and beauty, and many of the
great poets, from Homer and the author of Job down to Tenny-
son and the men of our own day, have had their fancy enlivened
by them, and in one form or another have celebrated their sweet-
ness and mystery and charm. Men of fancy have compared the
Pleiades to a swarm of fire-flies, to bees, to a rosette of diamonds,
and to shining dew-drops, while less ecstatic minds have com-
pared them to a hen and chickens and the seven virgins. Even
people who do not know them by sight and have not felt "the
sweet influences of Pleiades," vaguely recall some story about a
lost Pleiad that stirs an emotion suggesting something romantic
and sad.
The Pleiades form, in truth, a delightful group of twinkling,
unfathomable stars, singularly fascinating and singularly persist-
ent in their brilliancy. Of the six that can usually be seen with
the naked eye, all but one are of the fourth magnitude and are
not much brighter than the tiny Alcor, Mizar's companion. Yet
often when the moon is full and many of even the third-magni-
tude stars axe practically extinguished by its greater brilliancy,
the Pleiades hang in the sky like a small luminous cloud dis-
tinctly visible and commanding admiration. When the moon is
dark, they are hardly less conspicuous than a first-magnitude
star, and one sometimes fancies what a splendid great star they
would seem to us if they would only huddle a little closer to-
gether so that we could see them as one.
Still, even on the surface of the sky just as we see them, they
124
The Mystery of the Pleiades 125
are not so close together as we often regard them. The full moon,
which to casual observation seems to cover an area so much
greater than they, can move about among them, most of the time
covering only one visible star at a time. This occurs when the
Pleiades are occulted by the moon, a phenomenon that is some-
times seen, since the Pleiades lie within four degrees of the center
of the Zodiac, in which, as we know, lies the path of the moon.
The whole constellation covers a space of a little more than three
square degrees, while the apparent diameter of the moon is but
little more than half a degree. It is hard to believe that four or
five moons together would be required to cover the little dipper
of the Pleiades from our view entirely, but it is true. The moon
appears much larger to us because of its brilliancy. Its size as
Asterope
Ta X9 eta
Electro
THE PLEIADES
compared with other objects in the heavens is very deceptive.
The principal stars of the Pleiades form an outline resembling
a tiny short-handled dipper. I have more than once been asked
if this was the Little Dipper. The Pleiades, of course, lie in an
entirely different place from the true Little Dipper, the one that
has Polaris at the end of its handle. The Pleiades lie in the con-
stellation Taurus. They rise just an hour earlier than Aldebaran
and are visible at the same seasons as that bright star. We see
126 The Friendly Stars
their shining light during the first cold evenings of autumn. O
Hallowe'en they are about half-way up from the horizon betwee
nine and ten o'clock. In the winter, the Pleiades are high in th
sky during the early evening, tending more and more towarc
the west as the season advances. In March they set between nin
and ten o'clock, and in April they disappear from the evenin
skies.
Any one can see the six principal stars of the Pleiades; man
can see seven, and sharp eyes can distinguish anywhere from eigt
to eleven. There are so many stars in the group that are jm
beyond the limit of easy visibility that to any eye the numte
varies according to the clearness of the atmosphere and othe
physical causes. Even from moment to moment they twinkle i:
and out of our vision. It was no doubt this characteristic tha
suggested the simile of a "swarm of fire-flies." There are, in fac
more than three thousand stars in this small group. They canno
all be seen with a telescope, but they have recorded the fact c
their existence on the photographic plates.
Photography, too, has disclosed the extent and complexity o
a vast body of nebulous matter "a cosmical fog," it has beei
called which hangs around the Pleiades like a great veil, gathei
ing itself into wisps here and there and in some instances makinj
something like festoons from one star to another. Slight traces o
this great cloud of nebula were first seen visually through tb
telescope, but only within the last few years have the extent an<
significance of the enveloping cloud been learned.
The chief stars of the Pleiades group have the same genera
motion in the heavens, and more than forty of the fainter one
have been observed and are found to be moving along with tin
system.
The Pleiades appear to be a great system of stars, perhap
evolving from the tremendous mass of nebula in which it i
engulfed. In comparison with Alcyone and other Pleiades 0113
sun is small indeed, and at the same distance would be visible
only with a good telescope. The distance of the Pleiades froir
w is about 400 light years.
In keeping with the magnificent scale on which the whole
system is constructed is the distance of the individual stars in 11
from each other. The diameter of the duster is of the order oi
thirty light years. Yet so distant are they from us that with thii
The Mystery of the Pleiades 127
vast space between the individuals the group shows to us only
the tiny cluster of twinkling stars, small enough barely to cover
the jewels in Orion's belt.
We may know more about the Pleiades as time goes on, but
they will never be any nearer to us or any brighter to our view.
They may indeed in future ages be even less bright, for every
second of our lives the distance between us and them is increased
by many miles. Our sun, with us, his children, is travelling
through space away from the Pleiades at the rate of about six
miles a second, while they are headed towards another part of
the universe and travelling at no less a rate. And yet, in seeming
contradiction to this, under an old Hindu conception of the ma-
terial universe, Alcyone, the brightest star in this group, was
supposed to be the center around which our sun with all its
planets and other suns with their planets were revolving in
immense orbits. This idea is not correct, even though it reappears
perennially, supported not by astronomers or scientists but by
speculative philosophers expounding the metaphysical thought
of the East.
The nine brightest stars of the Pleiades bear the names of
Atlas and his seven daughters and their mother, the nymph
Pleione. Atlas is the star at the end of the handle of the dipper
formed by the stars. Pleione, the mother, which lies just above
him, may be the lost Pleiad, since it is difficult for some persons
to see her. Alcyone, the brightest of them all, is of the third
magnitude, and lies at the joining of the bowl and the handle
of the dipper. Electra, the second star in point of brightness, lies
in the bottom of the dipper and is of the fourth magnitude. It
is but a shade brighter than Atlas, and the ordinary eye can see
no difference between the two. Maia, which lies about the middle
of the top rim of the bowl; Merope, in the back corner of the
bowl, and Taygeta, at the front edge of the brim, are all fourth-
magnitude stars. Celaeno, a little fainter, is about half-way be-
tween Electra and Taygeta; and Asterope, the faintest of her
family, lies a short distance above Taygeta. Asterope is of the
sixth magnitude, and very few persons can see it without the aid
of a glass.
From the persistence of the story of the "lost" Pleiad and the
almost universal reference to them as "the seven stars," it has
been suggested that one of the fainter ones may formerly have
128 The Friendly Stars
been brighter, but it is not certain which one. Electra is sonic
times mentioned as having veiled her face on account of thi
destruction of Ilium, and sometimes as having been carried oi
by Canopus. If she is the lost one, it is in no physical sense, fo
she still shines the second in brightness of them all. The like i
true of Merope, often reputed to be the lost one because sh<
married the mortal Sisyphus, but she is still among the SH
brightest Pleiades. Celaeno has been reported to have been strud
by lightning and thus lost, fading to the seventh magnitude anc
therefore difficult to see with the naked eye. Pleione, the mothei
star and of the seventh magnitude, is the one commonly assignee
the role of the lost Pleiad.
XXVIII
From the Twins Back to the Hunter
n EMINI is the constellation of the Twins, already described,
^It rises about the same time as Taurus and is next north of
it. Gemini is the fourth constellation and third sign of the
Zodiac. The sun passes through it from June 18th to July 18th.
Hence it can best be seen from October to May,
CAMS MINOR
Canis Minor lies south of Gemini and is already known to us.
It is the constellation containing Procyon; and though it has
seven other stars, none of them is of any particular interest. It
represents a very small dog on the back of a' unicorn. The Uni-
coni is a constellation in itself, known as Monoceros, but it is
insignificant and contains no star brighter than the fourth
magnitude.
CANCER
This is a small constellation containing no star brighter than
the fourth magnitude, and out of its fifteen naked-eye stars only
four are as bright as that. It is the fourth sign and the fifth con-
stellation of the Zodiac After leaving Gemini, the sun passes
through Cancer from July 18th to August 7th, The constellation
includes most of the stars in the region between Pollux and
Regulus. Its most interesting feature is Praesepe, a beautiful star
duster shaped somewhat like a beehive and lying about ten
degrees south of Pollux. It is visible to the unaided eye and a
particularly beautiful object in a small telescope or binocular.
229
130
The Friendly Stars
LEO
Leo the Lion is the constellation containing the first-magni-
tude star Regulus, with which we are already familiar. Leo is the
fifth sign and the sixth constellation of the Zodiac, and the sun
is travelling through it from August 7th to September 14th. It
is best seen from January to June. It is supposed to represent a
couchant lion and is one of the rather conspicuously displayed
constellations.
It contains three stars of the second magnitude, Beta, Gamma,
and Delta Leonis. Gamma is the brightest star in the blade of
the Sickle. Beta, more frequently called Denebola, Delta, some-
+10-
10"
LEO OR THE LION
times called Zosma, and Theta form a conspicuous triangle.
Zosma lies in the back of the lion, at the beginning of the tail,
and Denebola marks the tuft at the end of the tail. The triangle
is visible in the northwest in the early summer for nearly two
hours after the Sickle has set.
COMA BERENICES
Just east of Leo is a small duster of stars called Berenice's Hair.
It is interesting mainly because of its delicate beauty.
This brings us back to Bootes in our circuit of the constella-
tions south of those surrounding the pole and north of the
equator. The next round will include the constellations coming
within our view that lie either in part or wholly south of the
equator.
XXIX
Constellations Wholly or in Part South of
the Equator
VIRGO
COUTH of Coma Berenices and Bootes lies Virgo, the sixth
sign and the seventh constellation of the Zodiac It lies about
half north and half south of the equator and is one of the largest
of the constellations, but not one of the richest in stars. Virgo
contains only about thirty-eight or forty naked-eye stars within
its boundaries. One of these is Spica, already known to us. The
next brightest is Gamma, a remarkable binary lying about ten
degrees north of Spica. It has a period of one hundred and eighty-
five years. It is of the third magnitude. All the others are of the
third magnitude or less. The sun occupies Virgo for forty-three
dayC passing through it from September 14th to October 29th.
Its stars being comparatively faint and much scattered, Viigo is
difficult to trace. It is supposed to represent a goddess with wings,
bearing a sheaf of wheat in one hand. Spica, as we have noted,
represents the ear of wheat. The constellation occupies all the
space from Leo to Libra on the west and east, and from Bootes
on the north to Hydra on the south. Denebola, Spica, Arcturus
and Cor Caroli form a large diamond, almost fifty degrees in
length, called "the diamond of Virgo."
LIBRA
Libra, or the Scales, is a small constellation lying wholly south
of the equator, into which the sun passes when it leaves Virgo on
October 29th. It occupies this constellation until November 21st
131
132
The Friendly Stars
10*
LIBRA OR THE SCALES
Libra has no star brighter than the third magnitude. Its chief
stars form a four-sided figure that is easily identified.
Libra is visible during the summer months crossing from
southeast to southwest, where it disappears in November.
SCORPIUS
Scorpius is known to us through its brightest star, Antares. It
has in addition four stars of the second, seven of the third, and
nine of the fourth magnitude. It is the ninth constellation and
the eighth sign of the Zodiac, and is occupied by the sun from
November 21st to December 16th. Scorpius is the most southerly
of the constellations marking the path of the sun, and is farther
south than any other constellation of which we have a complete
view. But inasmuch as the sun does not pass through the most
southerly part of Scorpius, it is not the constellation that con-
Constellations South of the Equator 133
tains the point farthest south in the Zodiac We can see it from
about June 1st until late in October.
SAGITTARIUS
Sagittarius is the ninth sign and tenth constellation of the
Zodiac. In it lies the most southerly point of the Zodiac. The sun
enters it on December 16th and reaches the most southerly point
of its path five days later, December 21st. Sagittarius lies in the
Milky Way east of Scorpius. It can be easily recognized by a little
figure resembling a dipper turned upside down, an asterism
known as the "Milk Dipper" because it lies in the Milky Way. It
is very conspicuous during August and September.
30
SAGITTARIUS OR THE MILK DIPPER
Sagittarius represents a centaur in the act of shooting an arrow.
The curved line of stars represents the bow; the one extending
into the Milky Way and the one farthest east in the Dipper
represent the arrow and the bent arm pulling the cord. Sagit-
tarius has two stars of the second magnitude, nine of the third,
nine of the fourth, and twenty-eight of the fifth magnitude. The
134 The Friendly Stars
Milk Dipper is almost seventy degrees directly south of Vega
and is almost as far south of the equator as Vega is north of it.
OPHIUCHUS AND SERPENS
Ophiuchus and Serpens also lie on both sides of the equator.
They form a sort of combination constellation that occupies the
space between Hercules on the north and Scorpius on the south.
Ophiuchus and Serpens contain no very bright stars. The com-
bined figure represents a man bearing a serpent The two legs
of Ophiuchus run down to Scorpius, and the head bumps into
the head of Hercules, which is on the southern end of that
constellation. The serpent is more easily traced. Its head is just
south of the Northern Crown, and thence it winds down along-
side the head of Hercules, across Ophiuchus, and up on the
eastern side of him to Aquila.
Celestial cartographers have divided the single constellation
into two distinct and separated parts called* Serpens Caput or
Head of the Serpent and Serpens Cauda or Tail of the Serpent.
Serpens is a distinct and pretty line of small stars, fairly dose
together and sometimes almost in pairs, winding around through
this region of the skies; and it is particularly well defined in
August and September, when it is rather low in the southern
heavens.
CAPRICORNUS
Capricornus, or the Sea Goat, the tenth sign and eleventh
constellation of the Zodiac, lies southeast of Aquila. The sun oc-
cupies it from January 18th to February 14th. It has no con-
spicuous stars, and no figure definitely outlined that can be
described; and yet on a clear night the comparatively faint stars
dancing about in it may suggest a goat, if one does not try to
be too definite. Alpha and Beta, which are in the head of the
Goat, lie about twenty degrees south of Altair and point towards
it They are about two and one-half degrees apart, and are
attractive out of all proportion to their brilliancy. Near Alpha is
a faint fifth-magnitude star that is even a better test of vision
than AJcor. Capricornus lies east of Sagittarius and south of the
Dolphin.
Constellations South of the Equator 135
AQUARIUS
Aquarius covers the part of the Zodiac that the sun occupies
from February 14th to March 14th. The best time to observe the
constellation is when it is farthest from the sun, in August,
September, October, and November. Aquarius has three stars of
the third magnitude and none brighter. It, is of a peculiar and
straggling shape, extending around Capricornus on the north
and east. The eastern part of it is south of Pegasus, and the west-
ern part is south of Delphinus. It is supposed to represent a man
pouring water from an urn. Its distinctive feature to the naked
eye is a waving line of faint twinkling stars that somewhat
suggest a stream of water, and which lead down to our old
acquaintance Fomalhaut, in the mouth of the Southern Fish
(Piscis Austrinus). A bright Y-shaped asterism marks the water
jar. Aquarius is the eleventh sign and the twelfth constellation
of the Zodiac.
PISCIS AUSTRINUS
Of this constellation all we need to know is that it consists of
Fomalhaut and the few fifth-magnitude stars surrounding it.
CETUS
Cetus is a large constellation lying almost entirely south of
the equator. It represents a huge sea monster and is sometimes
called the Whale. The head, marked by a small pentagon of
stars, is on the equator and lies directly below Aries, about
twenty-two degrees south of the principal star (Hamal). The
body stretches along below Pisces and down to Aquarius, over
a distance of more than forty degrees. The body is outlined by
a four-sided figure easily distinguishable in this rather sparsely-
starred region, and the tail is marked by the only second magni-
tude star in the constellation a pretty yellow star sometimes
called Diphda. The most noted object in Cetus is the star Mira
(The Wonderful), its Greek letter name being Omioron CetiL
It is a remarkable variable star and changes in light all the way
from the second to the ninth magnitude. It is bright enough to
The Friendly Stars
be visible about a month or two each year, and reaches a maxi-
mum of brightness about every eleven months. However, its
maxima are not easily visible each year because some occur at
seasons of proximity to the sun. Sometimes it is barely visible
and at other maxima may attain the second magnitude. Once,
in 1779, it is reported to have been as bright as Aldebaran. It
has been under observation for more than three hundred years.
ORION
Orion is the most brilliant of all the southern constellations.
It has been fully described in the chapter on "Orion's Bright
Stars." It rises just after Taurus and is visible from late October
to May.
LEPUS
Lepus, or the Hare, is a small constellation just south of Orion.
It is very pretty in the winter, but too low down in the sky to
be seen dearly except when Orion is well up in the heavens.
ERIDANUS
Eridanus is a stream of stars beginning just west of the Orion
Nebula and meandering west and south among the stars until it
disappears below the southern horizon. Achernar, its only first-
magnitude star, is too far south for us to see it. Though most of
the stars are faint, the constellation is easily traced because so
few stars lie near it.
CANIS MAJOR
Canis Major, or the Great Dog, lies just east of Lepus and
south of Monoceros. It can always be identified by its bright star,
Sirius. Canis Major represents a dog standing on his hind feet
and pawing in the air in front of Lepus, the Hare. Sirius marks
the nose of the dog; Adhara, a star nearly as bright as the first
magnitude, is in the flank; and Mirzam, or Beta, scarcely less
Constellations South of the Equator 137
bright, is in one fore-paw. There are two other second-magnitude
stars, making the constellation, as a whole, one of considerable
brilliancy, even without the great Sirius. It contains forty-one
stars that can be seen without a glass.
HYDRA
Hydra, the Water Snake, is a straggling constellation that
covers between ninety and one hundred degrees in its length,
and has but one star of any considerable brightness. This is a
second-magnitude star, sometimes known as Cor Hydrae (the
Heart of the Snake), sometimes as Alpha Hydrae, and sometimes
as Alphard, the Solitary One. It is a reddish star, about twenty
degrees south and a little west of Regulus; and, as its name in-
dicates, Alphard has no other 'bright star very near it.
Cor Hydrae rises about half an hour later than Regulus,
reaches the meridian three-quarters of an hour earlier, and sets
two and one-half hours before Regulus disappears. The Water
Snake itself has its head directly south of Praesepe in Cancer
and about half-way between Procyon and Regulus. The body
runs southeasterly (outlined by Alphard and numerous faint
stars), below Leo and Virgo, and ends under Libra. Except for
its one bright star, Hydra is of no particular interest.
The back of Hydra serves as a resting-place for two very pretty
constellations known as Corvus the Crow and Crater the Cup.
Corvus lies a little to the southeast of Spica, and has four prin-
cipal stars forming a four-sided figure with a little star out at
one side, making the outline somewhat resemble that of Libra.
The four stars are rather bright third-magnitude ones, and the
constellation is a conspicuous one during the spring and early
summer months when Virgo and Leo are in prominent places
in the sky.
PISCES
Pisces is the twelfth sign and first constellation of the Zodiac
It has no bright stars, and is best described as the body of stars
occupying the space from Aquarius to Aries and running bdow
Andromeda and Pegasus and north of Cetus.
138 The Friendly Stars
Pisces is supposed to represent two fishes tied together with
ribbons, a very inappropriate combination; and it is not im-
possible to imagine that the faint stars running through it do
outline something of the sort, but certainly not with any defi-
niteness. The reviser of this book maintains that the lines repre-
senting the cords or ribbons originally were streams of water
sprayed from the mouths of the two fishes and splashing against
the back of Cetus.
Pisces should not be confused with Piscis Austrinus, or the
Southern Fish, which is an entirely different constellation. The
most important thing about Pisces is that in it lies the point
where the ecliptic, or path of the sun, crosses the equator. This
point is passed by the sun on its way north in the spring and is
called the vernal equinox. The line running from one pole to
the other and passing through the vernal equinox is the one
from which astronomers measure the right ascension of the stars
(equivalent to longitude on the earth). For this reason Pisces is
an interesting constellation, and it is to be regretted that it has
no bright star to mark so important a point. However, since the
vernal equinox slowly moves, occupying each of the twelve Zo-
diacal constellations in turn, over an interval of 25,000 years,
no star could represent the equinoctial point for very long.
XXX
Individuality of the Stars
TA7E ought now to begin to feel at home in the presence of
the general company of stars. We have been introduced to
most of the choicer and greater individuals among them and
have had a general view of their brilliant assemblage as it ap-
pears from night to night and from season to season and a slight
insight into their common life. If any permanent relation is to
ensue we must now each for himself make our own friends
among them. What most interests one may not most interest
another. We do not feel alike in regard to people or other ob-
jects in nature, so why should we in regard to the stars? The
more individuality any thing or person has, the surer are we to
have a decided feeling of attraction or repulsion for it, a readi-
ness to admit it to our regard or to let it pass with the unnum-
bered individuals that make no impression upon us.
More than any other natural objects, the stars, as they appear
to us in the skies, seem to me to have individuality. Each lovely
flower that we see is one of a species, and however much charac-
ter we may find in the species, every individual is known only by
its being a duplicate of thousands of others in petal, sepal, sta-
men, and anther. The shy hermit-thrust and the friendly robin
in then- perfect normal state must conform to then* kind even to
the color of their bills. But there is only one Vega, one Gapella,
one Arcturus, and they are no more duplicated in nature than
they are in name.
What the general character of a star assumes to us depends
upon ourselves, the peculiarities to which we are sensitive and
the play our fancy takes in the interpretation of them. But the
traits that go to make up this general character have their basis
in facts and are by no means products of a freakish imagina-
tion. Nearly every one has some sensitiveness to color and will
139
140 The Friendly Stars
receive an impression when he marks Antares as red, Vega as
bluish, Castor as tinged with green, and the various other stars
as having their own peculiar tints. This will have an additional
meaning, perhaps, when he remembers that these great white
stars with tints of various colors represent extremely hot stars.
It will then be but natural to remember that Capella, Procyon,
Pollux, and Arcturus and the other stars of a like yellow hue are
somewhat cooler; while Antares, Betelgeuse, and Aldebaran
and similar red stars are the coolest of all. Betelgeuse even al-
lows his eyelids to droop at intervals and thus becomes a variable
star, which is thought to be one of the marks of advanced age in
star life.
One must also get some impression of individuality as he
learns something of the motion and distance and dimensions of
a star. Our personal estimate of a star and relation to it can-
not but be influenced by such a fact as that Spica and Deneb
are twelve and forty times respectively more distant than com-
paratively near Altair. Or we may learn that one star whirls
around its companion in seven hours and another spends hun-
dreds of years accomplishing the same task. One star may fly at
the rate of two hundred miles in a second and another loiters
along at a pace scores of times slower. One star is plunging
towards us and another is receding from us, and whatever its
rate or direction, each star is pursuing its own peculiar path.
The length of its stay with us, the time of year that we see it
most, and the personal association we have with it must also
have some effect on our relation to a star. There must always be
less of intimate pleasure in the presence of a star like Fomal-
haut, for instance, which comes for only a few months each year
and makes a short, swift passage along the southern edge of our
skies, than with such stars as Capella and Vega, who turn their
shining faces towards us throughout the entire night so many
months in the year. There is likely to be more warmth of feel-
ing for the bright Spica, who shines during all the rich soft
nights of summer, than for the much brighter Rigel, who dances
along almost exactly the same path during the cold, crisp win-
ter nights. Certain stars that may have the intensest charm and
companionability for us if we first learn to know them as they
hang during the rich black nights under the great dome that
arches over spacious fields and valleys, may scarcely attract a
Individuality of the Stars 141
passing thought from us if we meet them first in the narrow al-
leyways of the city streets, or even in the hazy, half-lighted at-
mosphere that envelops the higher points in the city.
Even the name of a star imparts some flavor to one's general
notion of it. Some names are essentially feminine, some distinctly
masculine, some have a meaning that cannot be overlooked, and
some appeal to one's fancy by mere association of sound.
As we come into closer acquaintance with the stars and give
heed to them, such characterization comes about as naturally
as it does with any other objects that play into our lives. In my
journal of out-door things I find mention of perhaps thirty or
more stars that seem to me to have well-defined traits which
are indissolubly attached to my idea of the star. Antares, for
example, seems old but important and impressive, Capella fair
and mature, Vega young and fresh and joyous, Arcturus full of
dignity, Sirius brilliant without much impressiveness, Betel-
geuse gloomy even to the point of being foreboding, and sug-
gestive of the sullen redness of the light before whose warning
eye the swift electric trains come to a dead stop. Dubhe and
Merak seem fair and smiling as they graciously point the way
to the North Star, Mizar suggests friendliness, Alcor faithful-
ness, Aldebaran sturdiness, the Pleiades delicate charm, Fomal-
haut serenity, Castor and Pollux gentleness and kindness and
affection, Mira instability, and Polaris its opposite stability and
responsibility.
Many more might be added to this list, but I have no desire
or expectation that others may have the same impressions that
I have concerning individual stars. Circumstances may lead them
to lay stress upon quite different traits which are as truly char-
acteristic of the star as the ones that have appealed most to me.
These have been mentioned to indicate the pleasant familiarity
that one may assume with the individuals composing this great
body of nature that lies above our eyes every night of our lives,
and to create this sort of an interest in them has been the sole
aim of this book.
Index
ACHERNAR (Alpha Eridani) ,11; pro-
nunciation, 11; magnitude, 81.
Acrux (Alpha Crucis), 11, 77, 81.
Adara (Epsilon Canis Majoris) , 136.
Albireo (Beta Cygni) , a double star,
54.
Alcor, companion to Mizar, 77, 106-
107.
Alcyone, 127.
AMebaran (Alpha Tauri) , pronunci-
ation, 11; chapter xi; color, 48; in
constellation Taurus, 48; location,
48; meaning of name, 49; winter
star, 49; brilliancy, 50; lies in
moon's path, 50; "royal" star, 50;
when visible, 50; magnitude, 81.
Alderamin (Alpha Cephei) , 109.
Algenib (Gamma Pegasi) , in the
square of Pegasus, 116.
Algol (Beta Persei) , 120; known as
"The Ghoul" or winking star, 120;
magnitude, 120,
Alioth (Epsilon Ursae Majoris), in
the Great Dipper, 105.
Alkaid (Eta Ursae Majoris) , 105.
Almach (Gamma Andromedae) , 120.
Alpha Andromedae (Alpheratz) , 119.
Alpha Arietis (Hamal) , 122.
Alpha Canum Venaticorum (Cor
Garoli), 111.'
Alpha Cassiopeiae (Schedar) , 109.
Alpha Centauri (Rigil Kent), 12;
pronunciation, 10; double star, 12;
nearness to earth, 12; Southern
Star, 12; magnitude, 81.
Alpha Cephei, 109.
Alpha Coronae Borealis (Alphecca),
90.
Alpha Crucis, 11; pronunciation, II;
magnitude, 81.
Alpha Draconis as Pole Star, 102.
Alpha Hydras (Cor Hydrae) , 137.
Alpha Pegasi (Markab) , 116.
Alpha Persei (Mirfak) , in the seg-
ment of Perseus, 120.
Alpha Ursae Majoris (Dubhe) , 105.
Alpha Ursae Minoris (Polaris) , 6,
101.
Alphecca (Alpha Coronae) , chief star
in Corona Borealis, 112; rising of,
112.
Alpheratz (Alpha Andromedae) , 116,
119.
Altair (Alpha Aquilae) , 11; pro-
nunciation, 11; chapter vm; how to
locate, 35; when visible, 36-59;
development, 39; distance from the
earth, 39; magnitude, 81.
Alwaid (Beta Draconis) , 110.
Andromeda, 117; the constellation,
117; diagram, 118; famous nebula,
119.
Antares (Alpha Scorpii) , 2; Southern
Star, 7; pronunciation, 11; chapter
nc; location, 40; Southern Star, 40;
when visible, 40-43; color, 43; in
the constellation Scorpius, 43; red
giant, 43; binary system, 44; dis-
tance from the earth, 50; "royal"
star, 50; magnitude, 81.
Aquarius (The Water Bearer) , 135;
related to Pegasus, 116.
Aquila (The Eagle), 115; stars of,
115.
Archer, the (Sagittarius) , 1 13.
Arcturus (Alpha Bootis), splendor,
2; pronunciation, 10; chapter rv;
brilliancy, 20; how to locate, 20;
rising time, 20-21; color, 21; diame-
ter, redjeiant, 21; distance from the
earth, 22; speed, 22; in the constel-
lation Bootes, 23; magnitude, 81;
part of the diamond 01 Virgo, 131.
Argo Navis, 99.
Arided, see Deneb.
Aries (The Ram) , 122; first sign of
the Zodiac, 122.
143
144
The Friendly Stars
Arrow, the (Sagitta), 115.
Asterism, 12, 99.
Asteropc, 127.
Atlas, a double star, 127; one of the
brightest stars in the Pleiades, 127.
Auriga (The Charioteer), 19; 120-
121.
BARNARD'S STAR, 89.
Becrux (Beta Gratis) , 11, 77.
Bellatrix, in Orion, 55.
Benetnasch, set Alkaid.
Berenice's Hair (Coma Berenices) , 90.
Beta Andromeda (Mirach) , 119.
Beta Aquilae, 115.
Beta Anetis (Sheratan) , 122.
Beta Auriga? (Menkalinan) , 121.
Beta Canis Majoris (Mirzam) , 156.
Beta Cassiopeia; (Caph) , 108.
Beta Centauri, 11; pronunciation, 11;
magnitude, 31.
Beta Cephei, 109.
Beta Ceti (Diphda) , 1S5.
Beta Crutis (Becrux) ,11; pronunci-
ation, II; magnitude, 81.
Beta Draconis (Alwaid) , 110.
Beta Leonis (Denebola) , 68.
Beta Pegasi (Scheat), 116.
Beta Persei (Algol) , 120.
Beta Ursae Majoris (Merak) , 106.
Beta Ursae Minoris (Kochab) , 103.
Betelgeuse (Alpha Orionis) , 3; pro-
mmtiatkm, 11; irregular variable,
52; red giant, 52; distance from the
earth, 54; magnitude, 81.
Big Dipper, set Great Dipper.
Binaries, spectroscopic, 97.
Binary systems, chapter xx.
Bootes, 23; 111-112.
Bull, the (Taurus) , 48, 123.
CANCER (The Crab) , 129; fourth sign
of the Zodiac, 129; Praesepe in, 129.
Canes Venatici (The Hunting-Dogs) ,
Canis Major (The Great Dog) , 136.
Canis Minor (The Smaller Dog),
109.
Canopos (Alpha Carinae) , brilliancy,
11; distance from the earth, 11;
pronunciation, 11; ran away with
one of the Pkiades, II, 128; South-
ern Star, 11; magnitude, 81.
Capella (Alpha Auriga), 3, 19; pro-
nundation, 10; chapter m; bril-
liancy, 17; how to find, 17; rising
time, 17-18; when visible, 17-18;
color, 18; rarefied body, 18; a
double star, 18-19, 92; magnitude.
81.
Caph (Beta Cassiopeiae) , 108.
Capricornus (The Goat), 134; rela-
tion to Auriga, 121; tenth sign of
the Zodiac, 134. 6
Carina, (The Keel) , 99.
Carlyle, Thomas, quoted, 99.
Cassiopeia, chapter xxiv.
Castor (in Gemini) , 57; brilliancy,
57; rising, 57; course, 58; supersti-
tion, 58; distance from the earth,
59; a multiple star, 59, 90.
Ceteno, 127.
Cepheus, chapter xxiv.
Cetus (The Whale) , 135.
Clusters, moving, 90.
Coma Berenices, 90.
Concerning the brightest stars, chap-
ter n.
Constellations, chapters xxi-xxix; for
details refer to constellation name.
Cor Caroli (Alpha Canum Venati-
corum), 111; part of the diamond
of Virgo, 131.
Cor Hydrae (Alpha Hydrae) , only
bright star in Hydra, 137.
Corona Borealis (Northern Crown),
112. ;
Corvus (The Crow) , 137.
Crab Nebula, 88.
Crater (The Cup) , 137.
61 Cygni, 34.
Cygnus (The Swan) , 34, 114.
Cynosura (Polaris) , the end of the
dog's tail, 102.
DELPHINUS (The Dolphin, or Job's
Coffin), 35, 38, 115.
Delta Andromedae, 119.
Delta Cassiopeiae, 108.
Delta Leonis (Zosma) , 130.
Delta Pegasi (Alpheratz) , 116, 119.
Delta Ursae Majoris (Megrez) , 105.
Deneb (Arided) , (Alpha Cygni),
head of Northern Cross, 6; pro-
nunciation, 11; chapter vn; rising
time, 30; when visible, 30-33;
meaning of the name, 32; color,
33; distance from the earth, 33;
supergiant, 33; magnitude, 81.
Denebola (Beta Leonis), location,
68; meaning of name, 68; part of
the diamond of Virgo, 131.
Diamond of Virgo, 131.
Diphda (Beta Ceti) , 135.
Distances of the stars, chapter xrx.
Dog Stars, the two, chapter xrv; see
also Procyon and Sirius.
Dolphin, the (Job's Coffin) , see Del-
phinus.
Double stars, chapter xx.
Index
Draco (The Dragon) , 109-110.
Dubhe (Alpha Ursae Majoris) , 105.
Dust, interstellar, 71.
EINSTEIN'S THEORY OF RELATIVITY, 71.
Electra, 127.
Emerson, quoted, 4.
Enif (Epsilon Pegasi) , 116.
Epsilon Canis Majoris (Adara) , 136.
Epsilon Cassiopeia, 108.
Epsilon Lyrae, a double-double star,
^1.
Epsilon Pegasi (Enif) , 116.
Epsilon Ursae Majoris (Alioth) , 105.
Eridanus (The River) , 136.
Eta Aquilae, variable star, 115.
Eta Cassiopeiae, double star, 108.
Eta Ursse Majoris (Alkaid) , 105.
Etamin (Gamma Draconis) , 110.
FOMALHAUT (Alpha Piscis Austrini),
when visible, 2; Southern Star, 7;
pronunciation, 11; chapter x; bril-
liancy, 45; location, 45; rising time,
46; "royal" star, 46; nearness to
earth, 47; magnitude, 81.
GAMMA ANDROMEDA (Almach) , 1 19.
Gamma Aquilae, 115.
Gamma Cassiof>ei2e, 108.
Gamma Draconis (Etamin) ,110.
Gamma Pegasi (Algenib) ,116.
Gamma Ursae Majoris (Phecda) , 106.
Gamma Ursae Minoris, 103.
Gemini (The Heavenly Twins) ,
chapter XHI, 129; see also Castor
and Pollux.
Goat (Capricornus) , relation to
Auriga, 121.
Gravitation, 95.
Great Bear (Ursa Major), 12-15;
the stars of, chapter xxin; always
visible, 104; its stars form the
Great Dipper, 104.
Great Dipper, the 6, 105; see also
Great Bear.
Great Dog (Canis Major) , the, 136.
Guard stars, 102-103.
HADAR (Beta Centauri) , 11.
Hamal (Alpha Arietis) , chief star
in Aries, 122.
Heavenly Twins, v the (Gemini),
chapter XIIL
Harvard Photometry, 79.
Hercules, 110, 113; diagram, 113.
Hunting-Dogs, the (Canes Venatici) ,
111.
Hyades, the, 48-49, 90.
Hydra (The Water Snake) , 157.
INDIVIDUALITY OF THE STARS, chapter
XXX.
JOB'S COFFIN, see Dolphinus.
Jupiter, the planet, 15-16.
KAPPA CASSIOPEIA, 108.
Kappa Orionis (Saiph) , 55.
Kochab (Beta Ursae Minoris) , 103.
LATITUDE, 8.
Leo (The Lion) , 130; Denebola, 130;
fifth sign of Zodiac, 130; Regulus,
130.
Leonids, 69.
Lepus (The Hare) , 136.
Libra (The Scales) , 131.
Light, of the stars, chapter xvra;
stellar magnitude, 78-83; speed of
light, 87.
Little Bear, the (Ursa Minor) , chap-
ter xxii; north pole within its
boundaries, 102; Polaris, 102.
Little Dipper (Ursa Minor), see
Little Bear.
Little Dog, see Canis Minor.
Lost Pleiad, the, 127.
Lyra (The Lyre) , 29, 114.
MAGNITUDE OF THE STARS, 72-
Maia, 127.
Markab (Alpha Pegasi), 116.
Mars, the planet, 15-16.
Megrez (Delta Ursae Majoris) , 106.
Menkalinan (Beta Aurigae) , 121.
Merak (Beta Ursae Majoris) , 106.
Mercury, the planet, 15.
Merope, 127.
Meteors, 69.
Milk Dipper, the, in Sagittarius, 133.
Milky Way, 71.
Mira, the Wonderful (Omicron
Ceti) , 76.
Mirach (Beta Andromedae) , 119.
Mirfak (Alpha Persei) , 120.
Mirzam (Beta Canis Majoris) , 136.
Mizar (Zeta Ursae Majoris) , 77, 106;
first double star discovered, 94;
quadruple star, 96.
Monoceros (The Unicorn) , 136.
Moon, apparent diameter of, 125.
Multiple stars, 97.
NAMES OF THE STARS, chapter xro.
Nebula, Orion, 55.
Neptune, the god, associated with
Auriga, 121.
Neptune, the planet, 15.
Newton, Sir Isaac, 95.
North Star, the (Polaris) , 6, 101.
Northern Cross, the (Cygmis) , 6.
146
Northern Crown (Corona Borealis),
112.
Number of stars, chapter xvi.
OMICRON CETI (Mira, the Wonder-
ful), 155-136.
Ophiuchus and Serpens, 154; loca-
tion, 154; when visible, 154.
Orion, and a frosty night, 2; chapter
xn; bright stars in, 52; mythology,
52; sword of, 52; belt of, 55; most
admired, 55; nebula, 55; "trape-
zium," 55; when visible, 56; three
kings, 156.
PALOMAR OBSERVATORY, 75.
Parallax of a star, finding the, 88.
Pegasus (The Winged Horse), 116-
117.
Perseus, 119; segment of, 120.
Phecda (Gamma Ursae Majoris) , 106.
Photometer, 79.
Pisces (The Fishes) , 157.
Piscis Austrinus (Southern Fish),
155.
Planets, the, 15; colors of, 16.
Pleiades, the, 49; lost, 11, 127; mov-
ing cluster, 90; chapter xxvn; in-
fluence of, 124; location of, 124;
principal stars in, 125; brightest
stars of, 126; distance from the
earth, 126; enwrapped in cosmical
fog, 126; time of rising, 126; num-
ber of stars in, 127.
Pleione, the lost Pleiad, magnitude,
127.
Pluto, the planet, 15.
Polaris (Alpha Ursae Minoris) , 6,
101.
Pole Star, see Polaris.
Pollux, pronunciation, 11; in constel-
lation Gemini, 57; winter star, 57;
superstition, 58; distance from the
earth, 59.
Praesepe, a star cluster in Cancer, 90.
Procyon, pronunciation, 11; a winter
star, 65; in Canis Minor, 64;
meaning of name, 64; the smaller
Dog Star, 64; a double star, 65;
nearness to earth, 65; magnitude,
81.
Proper motion of a star, 92.
Proxima (Alpha Centauri) , 12.
Puppis, the Stern, 99.
Pyxis, the Compass, 99.
RADIO STARS, 88.
Red giants, nature of, 22, 43.
Regulus (Alpha Leonis) , pronuncia-
tion, 11; chapter xv; location, 66;
brilliancy, 67; when visible, 67;
The Friendly Stars
distance from the earth, 68; in con-
stellation Leo, 68; meaning of
name, 68; magnitude, 81.
Rigel (Beta Orionis) , a southern
star, 7; pronunciation, II; brilli-
ancy, 54; color, 54; distance from
the earth, 54; location, 54; rising,
54; a winter star, 54; magnitude!
81.
Rigil Kent (Alpha Centauri) , 10, 12.
Ring Nebula, the, 114.
Rising and setting of the stars, the,
chapter I.
River, the (Eridanus) , 156.
"Royal" stars, 50.
SAGITTA (The Arrow) ,115.
Sagittarius (The Archer), 115; ninth
sign of the Zodiac, 115.
Saiph (Kappa Orionis) , 55.
Saturn, the planet, 15-16.
Scheat (Beta Pegasi) ,116.
Schedar (Alpha Cassiopeiae) , 109.
Schmidt camera, 75.
Scorpius, 152; eighth sign of the
Zodiac, 152.
Segment of Perseus, 120.
Serpens (The Serpent) , 154; see also
Ophiuchus.
Sheratan (Beta Arietis) , 122.
Sickle, the (Leo) , 150.
Sinus (Alpha Canis Majoris) , depar-
ture of, 7; location, 7; southern
star, 7; pronunciation, 10; compan-
ion of, 22, 44, 64; brilliancy, 61;
Dog Days, 61; Dog Star, 61; in
Canis Major, 61; a winter star; 61;
course, 62; Orion's Dog, 62; rising,
62; when visible, 62; color 63; dis-
tance from the earth, 65; magni-
tude, 81.
Sound, speed of, 87.
Southern Fish, see Piscis Austrinus.
Southern stars, 7; chapter xxix.
Speed of light, 87.
Spica (Alpha Virginia) , southern star,
7; pronunciation, 11; chapter v;
brilliancy, 24; how to find, 24;
color, 25; distance from the earth,
25; hour of setting, 25; meaning of
name, 25; when visible, 25; mag-
nitude, 81; part of the diamond
of Virgo, 151.
Square of Pegasus, 116.
Stars, the, time of rising and setting,
5, 8; chapter n; pronunciation, 10-
11; colors of, 62-65; magnitudes,
81; binary systems, chapter xx;
multiple, 97; individuality of, chap-
ter xxx.
Index
147
Sun, the, distance from the earth, 87.
Sword of Orion, 55.
TAURUS (The Bull), 48, 123; the
Hyades in, 123; and Orion, 123;
the Pleiades in, 123; second sign of
the Zodiac, 123; stars in, 123.
Taygeta, 127.
Theta Leonis, 130.
Theta Orionis, double star, 94, 96.
"Three Kings," the, 55.
Thuban (Alpha Draconis) , formerly
the Pole Star, 102-
Trapezium in Orion, see Theta
Orionis.
Triangulum, stars in, 122.
Twins, Heavenly (Gemini) , chapter
XIII.
Two Dog Stars, the, chapter xrv; see
also Procyon and Sirius.
URANUS, the planet, 15.
Ursa Major, see Great Bear.
Ursa Minor, see Little Bear.
VEGA (Alpha Lyrae) , harbinger of
spring, 1, 2; rising, 6, 27-29; pro-
nunciation, 10; chapter vi; com-
pared with Arcturus, 26; brilliancy,
27; how to find, 27; in constella-
tion Lyra, 29; when visible, 29;
magnitude, 81.
Vela (The Sail) , 99.
Venus, the planet, 15-16.
Virgo (The Virgin), 131; sixth sign
of the Zodiac, 131.
Virgo, Diamond of, 131.
WAIN, 107.
White dwarfs, 22, 44, 64, 65.
Winged Horse, see Pegasus.
ZETA URSJE MAJORIS (Mizar) , 77.
Zosma (Delta Leonis) , 130.
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