Pulsating variables in NGC 3293, the open cluster with the most beta Cephei stars known

Abstract

Contains fulltext : 36371.pdf (publisher's version ) (Open Access)We carried out an extensive CCD photometry campaign of the open cluster NGC 3293 that contains eleven known beta Cephei stars. Preliminary results indicate that none of these is singly periodic. Several objects are among the most multiperiodic of these massive pulsators, giving us strong hope to perform precision asteroseismology in an open cluster for the first time. We also report a peculiar group of variables in NGC 3293 that is located near the low-luminosity end of the beta Cephei instability strip. The variability periods of these stars are too long for classical beta Cephei pulsation, but too short for binarity or rotational effects, or for SPB-type pulsation. In addition, we discovered about a dozen delta Scuti stars in the field