Light Variability among the Late-Type B Pleiades Stars

Over 5300 photoelectric Stromgren y differential observations collected during a 3-yr interval on nine late-type B Pleiades stars have been analyzed using the modified Fourier transform described by Scargle (1982) and by Horne and Baliunas (1986). Three variables, 23, 27, and 28 Tau, are identified. 23 Tau has had a stable period of 11.8 hr over the 3 yr covered by the observations. It exhibits variable hydrogen line emission and as such is probably a mild late type Be star. 27 Tau has apparently undergone a period change reminiscent of the 53 Per-type stars. If confirmed, the spectral type of this star, B8 III, would make it the coolest known member of that class. 28 Tau is often listed as a Be star. This star is probably multiperiodic. These three variables are suggested to be nonradial pulsators.