Catalog of Galactic β Cephei Stars

Abstract

Fonds zur Förderung der Wissenschaftlichen Forschung, project R12-N02 We present an extensive and up-to-date catalog of Galactic β Cephei stars. This catalog is intended to give a comprehensive overview of observational characteristics of all known β Cephei stars, covering information until 2004 June. Ninety-three stars could be confirmed to be β Cephei stars. We use data from more than 250 papers published over the last nearly 100 years, and we provide over 45 notes on individual stars. For some stars we reanalyzed published data or conducted our own analyses. Sixty-one stars were rejected from the final β Cephei list, and 77 stars are suspected to be β Cephei stars. A list of critically selected pulsation frequencies for confirmed β Cephei stars is also presented. We analyze the β Cephei stars as a group, such as the distributions of their spectral types, projected rotational velocities, radial velocities, pulsation periods, and Galactic coordinates. We confirm that the majority of the β Cephei stars are multiperiodic pulsators. We show that, besides two exceptions, the β Cephei stars with high pulsation amplitudes are slow rotators. Those higher amplitude stars have angular rotational velocities in the same range as the high-amplitude δ Scuti stars (Prot ≳ 3 days). We construct a theoretical HR diagram that suggests that almost all 93 β Cephei stars are main-sequence objects. We discuss the observational boundaries of β Cephei pulsation and the physical parameters of the stars. We corroborate that the excited pulsation modes are near to the radial fundamental mode in frequency and we show that the mass distribution of the stars peaks at 12 M⊙. We point out that the theoretical instability strip of the β Cephei stars is filled neither at the cool nor at the hot end and attempt to explain this observation. © 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A.