Pulsating B Stars Discovered by HIPPARCOS

Abstract

We present a classification of 267 new variable B-type stars discovered by Hipparcos, which results in, among others, a huge number of new Slowly Pulsating B stars and several supergiants with ? 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 beta 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 ? Cyg-type variations are situated between the ? Cephei stars and the Slowly Pulsating B stars, 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 have started in the course of 1996 and that is still ongoing.