The first four-color photometric investigation of the W UMa type contact binary V868 Mon

TL;DR

This study presents the first four-color photometric analysis of the contact binary V868 Mon, revealing its subtype, temperature difference, and a long-term orbital period increase likely due to mass transfer.

Contribution

It provides the first four-color light curves and detailed analysis of V868 Mon, including its classification, temperature difference, and orbital period variation.

Findings

V868 Mon is an A-subtype contact binary with 58.9% fill-out factor.

The temperature difference between components is 916K.

The orbital period is increasing at a rate of 9.38×10^{-7} day/year.

Abstract

The first four-color light curves of V868 Mon in the $B$ $V$ $R_c$ and $I_c$ bands are presented and analyzed by using the Wilson-Devinney method of the 2013 version. It is discovered that V868 Mon is an A-subtype contact binary (f=$58.9\,\%$) with a large temperature difference of 916$K$ between the two components. Using the eight new times of light minimum determined by the authors together with those collected from literatures, the authors found that the general trend of the observed-calculate ($O$-$C$) curve shows a upward parabolic variation that corresponds to a long-term increase in the orbital period at a rate of $dP/dt=9.38\times{10^{-7}}day\cdot year^{-1}$. The continuous increase may be caused by a mass transfer from the less massive component to the more massive one.