Photometric Study of W UMa Type Binaries in the Old Open Cluster Berkeley 39

TL;DR

This study analyzes four W UMa binary systems in the open cluster Berkeley 39 using photometric data, revealing subtype classifications, absence of third bodies, and correlations between period, mass-ratio, and temperature.

Contribution

It provides detailed photometric solutions for four binaries in Berkeley 39 and identifies correlations consistent with previous studies, enhancing understanding of contact binary properties in clusters.

Findings

Two binaries are W subtype, two are H subtype W UMa systems.

No third bodies detected in any of the four systems.

Identified correlations between period, mass-ratio, and temperature.

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 four W UMa binaries in the open cluster Berkeley 39 using the latest version of WD 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 vant Veer (1996) and Li et al. (2008).