Pulsating B Stars Discovered by HIPPARCOS (Abstract)

Volume 35 number 1 (2007)

C. Aerts

C. Waelkens

P. De Cat

K. Kolenberg

E. Kestens

M. Grenon

Abstract

(Abstract only) We present a classification of 267 new variable B-type stars discovered by Hippar cos, which results in, among others, a huge number of new Slowly Pulsating B stars and several supergiants with α Cyg-type variations. Our results clearly point out the bias towards short-period variables of earlier, ground-based surveys of variable stars. The position of the new b Cephei stars and Slowly Pulsating B stars in the HR diagram is compared with the most recent calculations of the instability strips. The new Slowly Pulsating B stars almost fully cover the theoretical instability domain. The supergiants with α Cyg-type variations are situated between the beta Cephei stars and the Slowly Pulsating B star, on the one hand, and previously known supergiants that exhibit micro-variations on the other hand. Finally, we introduce the follow-up study of the most interesting targets that we started in 1996 and that is still ongoing.