On X-ray pulsations in beta Cephei-type variables

TL;DR

This study investigates the presence of X-ray pulsations in beta Cephei-type stars using archival data, finding no significant evidence of such pulsations, and suggests that more sensitive observations are needed for conclusive results.

Contribution

It provides the first systematic search for X-ray pulsations in beta Cephei stars using Chandra and XMM-Newton data, highlighting the rarity or difficulty of detecting such phenomena.

Findings

No statistically significant X-ray pulsations found in the sample

Weak variability indication in beta Cru

Data quality may limit pulsation detection

Abstract

Beta Cephei-type variables are early B-type stars that are characterized by oscillations observable in their optical light curves. At least one Beta Cep-variable also shows periodic variability in X-rays. Here we study the X-ray light curves in a sample of beta Cep-variables to investigate how common X-ray pulsations are for this type of stars. We searched the Chandra and XMM-Newton X-ray archives and selected stars that were observed by these telescopes for at least three optical pulsational periods. We retrieved and analyzed the X-ray data for kappa Sco, beta Cru, and alpha Vir. The X-ray light curves of these objects were studied to test for their variability and periodicity. While there is a weak indication for X-ray variability in beta Cru, we find no statistically significant evidence of X-ray pulsations in any of our sample stars. This might be due either to the insufficient data quality or to the physical lack of modulations. New, more sensitive observations should settle this question.