New programs for determining the main parameters of open clusters

Abstract

A set of computer programs for the determination of the main parameters of open clusters, such as color excess, distance, and age, is developed. The set consists of two units. The first unit is designed to search for open clusters in wide fields using JHKs-photometry from various catalogs (2MASS, UKIDSS, VISTA) by identifying areas of high stellar density. The second unit determines the parameters of open clusters by fitting photometric diagrams. This is the unit described in the paper. Probable cluster members are identified by the proximity to the basic sequences on the J-(J - H) and Q-(J - H) diagrams. The color excess is determined by minimizing the deviations of Q values on the Q-(J - H) diagram. Ages and distance moduli are determined by comparing the color-magnitude diagrams with theoretical isochrones. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.