Photometric and Kinematic Studies of Open Clusters Ruprecht 1 and Ruprecht 171

Abstract

This study outlines a detailed investigation using CCD UBV and 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 UBV-data analyses, whereas membership probability calculations, structural and astrophysical parameters, as well as the kinematic analyses were based on 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)$$ E\left(B-V\right) $$ were obtained as 0.166±0.022$$ 0.166\pm 0.022 $$ and 0.301±0.027$$ 0.301\pm 0.027 $$ 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±0.16$$ \left[\mathrm{Fe}/\mathrm{H}\right]=-0.09\pm 0.16 $$ and [Fe/H]=‑0.20±0.20$$ \left[\mathrm{Fe}/\mathrm{H}\right]=-0.20\pm 0.20 $$ dex for Rup-1 and Rup-171, respectively. Ages and distances were based on both UBV and Gaia-data analyses; according to isochrone-fitting these values were estimated to be t=580±60$$ t=580\pm 60 $$ Myr, d=1469±57$$ d=1469\pm 57 $$ pc for Rup-1 and t=2700±200$$ t=2700\pm 200 $$ Myr, d=1509±69$$ d=1509\pm 69 $$ pc for Rup-171. The present-day mass function slope of Rup-1 was estimated as 1.26±0.32$$ 1.26\pm 0.32 $$ and Rup-171 as 1.53±1.49$$ 1.53\pm 1.49 $$. Galactic orbit integration analyses showed that both of the clusters might be formed outside the solar circle.