Photometric Study ofWUMa Type Binaries in the Old Open Cluster Berkeley 39

Abstract

The study of W UMa binary systems give a wealth of information about its nature as well as about its parent body (if any), like clusters. In this paper, we present the I passband photometric solutions of fourWUMa binaries in the open cluster Berkeley 39 using the latest version of W–D program. The result shows that, two binary systems are W-subtype W UMa binary systems and another two systems are H-subtype W UMa binary systems. No third body is found in any of the four systems. We found a correlation between the period and mass-ratio as well as temperature and mass-ratio for the respective variables which is similar to the relationship between mass ratio and total mass of the contact binaries as shown by van’t Veer (1996) and Li et al. (2008).