Investigation of orbital period changes in 9 contact binaries

TL;DR

This study analyzes the orbital period variations of 9 contact binary star systems over 12-15 years, revealing some systems with stable periods and others with non-linear changes due to mass transfer.

Contribution

It provides detailed orbital period analysis of 9 contact binaries using long-term photometric data, identifying period stability and non-linear variations with mass transfer insights.

Findings

4 systems show no orbital period change

5 systems exhibit non-linear (O-C) variations

Mass transfer occurs in both directions in different systems

Abstract

We present the results for orbital period analysis of 9 contact binaries (CBs). The photometric data analyzed in this work is collected using ARIES 1-m and 1.3-m telescopes as well as many ground and space-based photometric surveys. The precise orbital periods of the binary systems are studied using the long temporal baseline of data acquired over the last 12-15 years. The changes in the times of minimum brightness are calculated using (O-C) diagram. Out of these 9 CBs, four systems show no change in the orbital period with time while the remaining five systems show non-linear (O-C) variations with time. We derive mass transfer rates for these five CBs which suggests mass is being transferred from secondary to primary components in three systems while it is from primary to secondary components in the other two systems.