Revisiting the Fundamental Parameters of 49 New Star Clusters in Gaia DR2

Abstract

Abstract Reliable fundamental parameters of star clusters such as distance modulus, metallicity, age, extinction, and binary fraction are of key importance for astrophysical studies. Although a lot of new star clusters were identified from the data of, e.g., Gaia Data Release 2 (Gaia DR2), the fundamental parameters of many clusters were not determined reliably. This work makes use of the photometry data of Gaia DR2 and a good color–magnitude diagram (CMD) analysis tool, Powerful CMD, to determine the fundamental parameters of 49 new star clusters in detail. All CMDs are fitted carefully by both statistics and by eye, to make sure the CMDs are reproduced as well as possible. As a result, the fundamental parameters of 22 clusters are determined reliably, and those of the others are also determined as well as we can. Because the width of the main sequence in the color direction is used, combined with other widely used CMD features to constrain the fundamental parameters, the results of this work are more reliable than those reported by single-star isochrone fits. As a feature of this work, the primordial binary fractions and rotating star fractions of star clusters have been reported, which are useful for many works, in particular for some simulation research.