A study of open clusters Frolov 1 and NGC 7510 using CCD UBV photometry and Gaia DR2 astrometry

Abstract

We present reddening, photometric metallicity, age, and distance estimates for the Frolov 1 and NGC 7510 open clusters based on charge-coupled device (CCD) UBV photometric and Gaia data. Photometric observations were collected using the 1-m telescope of the TuBITAK National Observatory. Gaia data release 2 (DR2) proper motion data in the direction of two groupings were used to identify cluster membership. We determined mean proper motion values of (mu(alpha) cos delta, mu(delta)) = (- 3.02 +/- 0.10, - 1.75 +/- 0.08) and (-3.66 +/- 0.07, -2.17 +/- 0.06) mas year(-1) for Frolov 1 and NGC 7510, respectively. We used two-color diagrams to obtain E(B - V) color excesses for Frolov 1 and NGC 7510 of 0.65 +/- 0.06 and 1.05 +/- 0.05 mag, respectively. We derived the photometric metallicity of Frolov 1 as [Fe/H] = 0.03 +/- 0.03 dex and adopted a solar metallicity for NGC 7510. Based on these reddening and metallicities, we determined the distance moduli and ages of the clusters by fitting stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code (PARSEC) isochrones to the cluster color-magnitude diagrams. Isochrone-fitting distances for Frolov 1 and NGC 7510 are 2, 864 +/- 254 and 2, 818 +/- 247 pc, respectively, which correspond to the ages 35 +/- 10 Myr and 18 +/- 6 Myr. We also calculated mean Gaia distances and compared them with those given in the literature and in this study, concluding that our results are in good agreement with previous work. Finally, we calculated the mass function slopes and found them to be X = -1.21 +/- 0.18 for Frolov 1 and X = -1.42 +/- 0.27 for NGC 7510.