A catalog of new blue stragglers in open clusters with Gaia DR3

TL;DR

This study leverages Gaia DR3 data to identify 272 new blue and yellow straggler stars across 99 open clusters, significantly expanding the known population and providing insights into their formation and evolution.

Contribution

The paper introduces a new method combining Gaia DR3 data, isochrone fitting, and empirical CMD analysis to discover and classify blue stragglers in open clusters, increasing known counts.

Findings

Identified 272 new straggler stars in open clusters.

Increased the number of clusters with known stragglers by 22.2%.

Boosted the total known blue stragglers by 11.2%.

Abstract

The high-precision {\it Gaia} data release 3 (DR3) enables the discovery of numerous open clusters in the Milky Way, providing an excellent opportunity to search for blue straggler stars in open clusters and investigate their formation and evolution in these environments. Using the member stars from literature open cluster catalogs, we visually inspected the color-magnitude diagram (CMD) of each cluster and selected cluster candidates that potentially host blue stragglers. We then reassessed cluster memberships using the {\tt pyUPMASK} algorithm with {\it Gaia} DR3 and performed isochrone fitting to derive physical parameters for each cluster, including age, distance modulus, mean reddening, and metallicity. Finally, we empirically identified straggler stars based on their positions relative to the best-fitting isochrone, zero-age main sequence (ZAMS), and equal-mass binary sequence on the CMD. In total, we identified 272 new straggler stars in 99 open clusters, comprising 153 blue stragglers, 98 probable blue stragglers, and 21 yellow stragglers. Compared to the reported blue straggler catalogs based on earlier {\it Gaia} data, our results increase the number of open clusters with stragglers in the Milky Way by 22.2\%, and the total number of blue stragglers by 11.2\%.