A&A 475, 677-684 (2007)
X-ray emission from A-type starsC. Schröder and J. H. M. M. Schmitt
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
(Received 7 March 2007 / Accepted 10 September 2007)
Being fully radiative, stars of spectral type A are not expected to harbor magnetic dynamos and hence such stars are not expected to produce X-ray emission. Indeed, while the X-ray detection rate of such stars in X-ray surveys is low, it is not zero and some of the brighter A-type stars have been detected on different occasions and with different instruments. To study systematically the puzzle of the X-ray emitting A-type stars, we carried out an X-ray study of all A-type stars listed in the Bright Star Catalogue using the ROSAT public data archive. We found a total of 312 bright A-type stars positionally associated with ROSAT X-ray sources; we analyzed the X-ray light curves as well as searched for evidence of RV variations to identify possible late-type companions producing the X-ray emission. In this paper we present a list of X-ray active A-type stars, including the collected data about multiplicity, X-ray luminosity and spectral peculiarities.
Key words: X-rays: stars -- stars: activity -- stars: coronae -- stars: general
© ESO 2007