The Clusters AgeS Experiment (CASE). Variable stars in the field of the globular cluster NGC 362

TL;DR

This study monitored the globular cluster NGC 362 over 18 years, discovering over a hundred variable stars, including new types and detailed data on known variables, enhancing understanding of stellar variability in this cluster.

Contribution

The paper presents the discovery of over a hundred variable stars in NGC 362, including new types and detailed light curves, expanding the catalog of cluster variables and their properties.

Findings

Over 150 variable stars identified, with more than 100 new detections.

Discovery of specific variable types such as SX Phe, RR Lyrae, and eclipsing binaries.

Identification of interesting objects like binary blue straggler V20 and X-ray source V24.

Abstract

The field of the globular cluster NGC 362 was monitored between 1997 and 2015 in a search for variable stars. BV light curves were obtained for 151 periodic or likely periodic variables, over a hundred of which are new detections. Twelve newly detected variables are proper motion members of the cluster: two SX Phe and two RR Lyr pulsators, one contact binary, three detached or semi-detached eclipsing binaries, and four spotted variables. The most interesting objects among these are the binary blue straggler V20 with an asymmetric light curve, and the 8.1 d semidetached binary V24 located on the red giant branch of NGC 362, which is a Chandra X-ray source. We also provide substantial new data for 24 previously known variables.