# New variable stars in NGC 6652 and its background Sagittarius stream

## TL;DR

This study discovers nine new variable stars in the globular cluster NGC 6652 and its background Sagittarius stream, classifies some, and confirms cluster membership of an RR Lyrae star using Gaia data.

## Contribution

It reports the first identification of variable stars in NGC 6652 and analyzes their membership using Gaia proper motions, providing new insights into the cluster and its background.

## Key findings

- Nine new variable stars discovered in NGC 6652 field.
- Three variables associated with the cluster, field, and Sagittarius stream.
- Confirmation of one RR Lyrae star as a cluster member.

## Abstract

We conducted a variable star search on the metal-rich Galactic globular cluster NGC 6652 using archival Gemini-S/GMOS data. We report the discovery of nine new variable stars in the NGC 6652 field, of which we classify six as eclipsing binaries and one as SX Phoenicis stars, leaving two variables without classification. Using proper motions from Gaia DR2 and HST, albeit with some uncertainties, we find that the cluster, the field, and the background Sagittarius stream, have 3 of these variables each. We also reassess the membership of known variables based on the Gaia proper motions, confirming the existence of one RR Lyrae star in the cluster.