A Detailed Analysis of Close Binary OCs

Abstract

In this study, we analyzed the close binary open clusters CWNU 2666 and HSC 224, which are in close spatial proximity, using photometric and astrometric data from the {\it Gaia} DR3 catalog. Likely member stars were identified based on a membership probability threshold ($P\ge 0.5$), resulting in 106 and 146 members for CWNU 2666 and HSC 224, respectively. The mean proper motion components ($\hat{I}{¼}_{\hat{I}}\pm \cos \hat{I}´$, $\hat{I}{¼}_{\hat{I}}´$) were determined to be (0.646$\pm$0.155, -0.769$\pm$0.124) mas yr${}^{-1}$ for CWNU 2666, and (0.665$\pm$0.131, -0.728$\pm$0.107) mas yr${}^{-1}$ for HSC 224. The isochrone distances ($d_{\mathrm{iso}}$) were estimated as 1885$\pm$44 pc for CWNU 2666 and 1866$\pm$29 pc for HSC 224. The corresponding cluster ages ($t$) were derived as 160$\pm$15 Myr and 140$\pm$15 Myr, respectively. The astrometric and fundamental astrophysical parameters derived in this study demonstrate that the two open clusters are a close pair of open clusters.

6 pages, including 2 figures and 1 table, accepted for publication in the special issue of Contributions of the Astronomical Observatory Skalnate Pleso "Binary and Multiple Stars in the Era of Big Sky Surveys" (Kopal 2024)