Variability Study of EHB Stars in the Globular Cluster NGC 6752

TL;DR

This study investigates the variability of extreme horizontal branch stars in NGC 6752, discovering 17 variable stars including new types, a binary, and a dwarf nova outburst, enhancing understanding of stellar behavior in globular clusters.

Contribution

It provides the first comprehensive variability survey of EHB stars in NGC 6752, identifying new variables and a probable cluster binary, with implications for stellar evolution models.

Findings

17 variable stars detected, 14 newly identified

Discovery of a likely cluster member binary system

Detection of a dwarf nova outburst in the cluster core

Abstract

We present the results of a search for variable stars in the central part of the globular cluster NGC 6752. The monitored sample included 160 BHB and 107 EHB stars, respectively. A total of 17 variables were detected of which 14 are new identifications. Five variables are BHB/EHB stars. We report also on identification of a detached eclipsing binary being likely a member of the cluster. Moreover, we detected an outburst of a dwarf nova located in the cluster core.