Identification of new low-mass members of the Alpha Persei open cluster by ROSAT. II

The present investigation examines possible optical counterparts to 130 X‐ray sources in the region of the α Persei open cluster (d ∽ 170pc, age ∽ 50 Myr) resulting from the analysis of three 22–25 ksec ROSAT PSPC pointings. In the same manner as for 73 X‐ray sources from a raster survey in α Per (Prosser & Randich 1998), CCD photometry is employed to obtain magnitudes and colors for stars/objects close to the X‐ray positions, with additional echelle and low‐dispersion Hα spectra provided for some stars. For almost 60 X‐ray sources, an optical counterpart with photometry acceptable for cluster membership is identified, some of which can be excluded from membership on the basis of discrepant radial velocity or X‐ray characteristics. On the order of 30 new members or likely members associated with X‐ray sources have been identified based on available data. A photometric rotation period has been obtained for one rapid rotator identified in X‐rays.