Ultraviolet photometry from the Orbiting Astronomical Observatory. XXIV. The Beta Cephei stars Delta Ceti and Gamma Pegasi.
Photometric data from the Wisconsin Experiment package on OAO-2 were obtained for six fl Cephei variable stars. The data were reduced according to the procedure described in the OAO-2/Wisconsin Experiment Package (WEP) Photometer Users Guide (NSSDC 74-02). For two of the stars, Cet and y Peg, there were enough data points to form reliable composite light curves at seven or eight ultraviolet wavelengths. The light curves are well represented by sine waves in phase with the blue light curve for each star. The amplitude of the light variation increases as one goes to shorter wavelengths. For the remaining stars (6 Oph, e Cen, K Sco, and A Sco), mean magnitudes and light ranges were obtained at several ultraviolet wavelengths. The mean, dereddened ultraviolet colors of all the observed stars were compared with the mean values for standard stars computed by Bottemiller. No significant differences were found. A new temperature scale for B stars, based on the dereddened color (1910 - V)0, is presented and used to calculate temperature variations and amplitude ratios for 8 Cet and y Peg. Subject headings: stars: Beta Cephei - stars: individual - ultraviolet: general