# Variable Stars in Young Open Cluster NGC 2244

## TL;DR

This study conducted a comprehensive variability survey of the young open cluster NGC 2244, identifying 245 variable stars, classifying their types, and assessing cluster membership probabilities using multi-wavelength data and Gaia proper motions.

## Contribution

It provides the first extensive variability catalog for NGC 2244, including classifications of young stellar objects and membership probabilities, combining optical, infrared, and Gaia data.

## Key findings

- 245 variable stars identified, including irregular and periodic types.
- Classification of 104 young stellar sources into various evolutionary stages.
- Majority of variables are confirmed cluster members with high membership probability.

## Abstract

We present results of a UBVIc variability survey in the young open cluster NGC 2244. In total, we found 245 variable stars. Most of them, 211 stars, are variables with irregular variations. Furthermore, 23 periodic variables were found. We also detected four candidates for delta Scuti stars and 7 eclipsing binaries. Based on the mid-infrared Spitzer and WISE photometry and near infrared JHKs 2MASS photometry we classified 104 young stellar sources among our variables: 1 Class I object, 1 Class I/flat spectrum object, 4 flat spectrum objects, 91 Class II objects and 7 transition disk objects. This classification, together with r'i'H$alpha IPHAS photometry and JHK UKIDSS photometry, were used for identification of pre-main sequence stars among irregular and periodic variables. In this way, 97 CTTS candidates (96 irregular and one periodic variable), 68 WTTS candidates (54 irregular and 14 periodic variables) and 6 Herbig Ae/Be stars were found. For 223 variable stars we calculated membership probability based on proper motions from Gaia DR2 catalogue. Majority of them, 143 stars, are cluster members with probability greater than 70 percent. For only 36 variable stars the membership probability is smaller than 20 percent.