The Hyades star Theta(1) Tau is one of four K0 III giants in this nearby (d approx. 45 pc) open cluster. It is also one of the brightest coronal X-ray sources in the Hyades, with Lx approx. 10(exp 30) erg/s. Because of the known photospheric composition and age of the Hyades, Theta(1) Tau is an excellent candidate to study the relationship between stellar activity and coronal abundances. ROSAT observed Theta(1) Tau during the All Sky Survey, and in a long (17 ksec) pointed observation in September 1992. When ASCA observed Theta(1) Tau for approx. 30 ksec in September 1995, its X-ray brightness had not significantly changed. We present the ASCA X-ray spectrum, and examine models of Theta(1) Tau consistent with both the ASCA and ROSAT spectra.

plus-circle Add Review

comment

Reviews