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

TL;DR

This paper provides a comprehensive photometric and kinematic analysis of open clusters Ruprecht 1 and Ruprecht 171, determining their fundamental parameters, membership, metallicities, ages, distances, and orbital origins using CCD UBV and Gaia DR3 data.

Contribution

It offers new detailed astrophysical parameters and membership probabilities for Ruprecht 1 and Ruprecht 171 based on combined UBV and Gaia data, including their potential formation outside the solar circle.

Findings

Ruprecht 1 has a color excess E(B-V)=0.166 mag and age ~580 Myr.

Ruprecht 171 has a color excess E(B-V)=0.301 mag and age ~2700 Myr.

Both clusters likely formed outside the solar circle.

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 $0.166\pm0.022$ and $0.301\pm0.027$ 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 $t=580\pm60$ Myr, $d=1469\pm57$ pc for Rup-1 and $t=2700\pm200$ Myr, $d=1509\pm69$ pc for Rup-171. The present-day mass function slope of Rup-1 was estimated as $1.26\pm0.32$ and Rup-171 as $1.53\pm1.49$. Galactic orbit integration analyses showed that both of the clusters might be formed outside the solar circle.