Photometric and kinematic studies of open clusters Ruprecht 1 and Ruprecht 171

Abstract

This study outlines a detailed investigation using CCD {\it UBV} and {\it Gaia} DR3 data sets of the two open clusters Ruprecht 1 (Rup-1) and Ruprecht 171 (Rup-171). Fundamental astrophysical parameters such as color excesses, photometric metallicities, ages, and isochrone distances were based on {\it UBV}-data analyses, whereas membership probability calculations, structural and astrophysical parameters, as well as the kinematic analyses were based on {\it Gaia} DR3-data. We identified 74 and 596 stars as the most probable cluster members with membership probabilities over 50\% for Rup-1 and Rup-171, respectively. The color excesses $E(B-V)$ were obtained as $0.166\pm 0.022$ and $0.301\pm 0.027$ mag for Rup-1 and Rup-171, respectively. Photometric metallicity analyses were performed by considering F-G type main-sequence member stars and found to be [Fe/H]=$-0.09\pm 0.16$ and [Fe/H]=$-0.20\pm 0.20$ dex for Rup-1 and Rup-171, respectively. Ages and distances were based on both {\it UBV} and {\it Gaia}-data analyses; according to isochrone-fitting these values were estimated to be $t=580\pm 60$ Myr, $d=1469\pm 57$ pc for Rup-1 and $t=2700\pm 200$ Myr, $d=1509\pm 69$ pc for Rup-171. The present-day mass function slope of Rup-1 was estimated as $1.26\pm 0.32$ and Rup-171 as $1.53\pm 1.49$. Galactic orbit integration analyses showed that both of the clusters might be formed outside the solar circle.

14 figures and 4 tables, article accepted for publication in Astronomische Nachrichten