The Einstein Observatory Survey of Stars in the Hyades Cluster Region

The authors report the results of an extensive X-ray investigation of the Hyades region and improve upon previous studies by using refined X-ray source detection algorithms and the complete set of Einstein Observatory IPC exposures covering the Hyades cluster region (a total of 63 1°×1° images). Using a somewhat more extensive and complete compilation of optical candidates, the authors have detected 66 out of 121 Hyades members falling in the combined fields of view. The authors have also computed 3σ upper limits for all the nondetected Hyades members and have derived maximum-likelihood X-ray luminosity functions for the Hyades stars in selected spectral type ranges, using both detections and upper limits.