The ROSAT all-sky survey catalogue of optically bright main-sequence stars and subgiant stars

We present X-ray data for all main-sequence and subgiant stars of spectral types A, F, G, and K and luminosity classes IV and V listed in the Bright Star Catalogue that have been detected as X-ray sources in the ROSAT all-sky survey; several stars without luminosity class are also included. The catalogue contains 980 entries yielding an average detection rate of 32 percent. In addition to count rates, source detection parameters, hardness ratios, and X-ray fluxes we also list X-ray luminosities derived from Hipparcos parallaxes. The catalogue is also available in electronic form via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html