New Beta Cephei stars in the young open cluster NGC 637

Abstract

Studying stellar pulsations in open clusters offers the possibility to perform ensemble asteroseismology. The reasonable assumption that the cluster members have the same age, distance, and overall metallicity aids in the seismic modelling process and tightly constrains it. Therefore it is important to identify open clusters with many pulsators. New pulsating stars of the Beta Cephei type were searched for among the members of the open cluster NGC 637. Thirty-one hours of time resolved V filter CCD photometry were obtained. The measurements confirmed two previously known variables, and revealed three new Beta Cephei stars plus one more candidate. All four pulsators have amplitudes high enough for easy mode identification and are multiperiodic. With four certain pulsating members, NGC 637 is now among the six open clusters richest in Beta Cephei stars. It is thus an excellent target for ensemble asteroseismology, and to tackle the question what separates pulsating from apparently constant stars in the Beta Cephei domain.

6 pages, 8 figures, A&A, in press

References in corpus (4)

• Beta Cephei stars in the ASAS-3 data. II. 103 new Beta Cephei stars and a discussion of low-frequency modes
• Optical and near-IR photometric study of the open cluster NGC 637 and NGC 957
• uvbybeta photometry of early type open cluster and field stars
• Towards ensemble asteroseismology of the young open clusters Chi Persei and NGC 6910

Cited by in corpus (6)

• Pulsating B-type stars in the open cluster NGC 884: frequencies, mode identification and asteroseismology
• Main-sequence variable stars in young open cluster NGC 1893
• Pre-main sequence variable stars in young open cluster NGC 1893
• Variable stars in the Sh 2-170 HII region
• Asteroseismology of $\beta$ Cephei stars: The stellar inferences tested in hare and hound exercises
• Long-term investigation of an open cluster Berkeley 65