58 open clusters investigated with UBVRI and Gaia eDR3 data

Abstract

ABSTRACT We present the results of the investigation of 58 open clusters using UBVRI CCD photometry (Johnsons-Cousins system) and Gaia eDR3 data. The membership probability of the stars in the cluster’s field was determined from a maximum-likelihood method using Gaia eDR3 astrometric data. The fundamental parameters of the clusters were determined using a robust global optimization method to fit theoretical model isochrones to UBVRI ground-based and Gaia eDR3 photometric data, respectively. We estimated mean proper motion, mean parallax, and fundamental parameters considering the member stars for 25 clusters. Based on the high quality Gaia eDR3 data, the remaining objects of the sample were found to be likely not real. The real clusters are situated from 900 to 3000 pc with ages from about 6 Myr to 2.5 Gyr. The results of the distances and ages obtained for both independent sets of data are in agreement indicating that our method to determine distances and ages using GBP and GRPGaia eDR3 data is reliable.