The First Photometric Study of the Binary System CSS J003106.8+313347

TL;DR

This study presents the first detailed photometric analysis of the W UMa-type binary CSS J003106.8+313347, determining its physical parameters and orbital characteristics using ground-based observations and advanced modeling techniques.

Contribution

It provides the first photometric and physical parameter determination of CSS J003106.8+313347 using MCMC and Gaia data, without requiring starspots for light curve modeling.

Findings

Mass ratio of 0.699 and inclination of 60.6 degrees.

System's position in contact binary region on the HR diagram.

Estimated masses, radii, and luminosities of both components.

Abstract

We performed the first photometric study of the CSS J003106.8+313347 W Ursae Majoris (W UMa)-type system based on ground-based observations. We extracted times of minima from our observations and proposed a linear ephemeris based on the increasing incline of the orbital period using a Markov chain Monte Carlo (MCMC) approach. The PHOEBE Python code and the MCMC approach were used for the light curve analysis. This system did not need starspots for the light curve analysis. Mass ratio, fillout factor, and inclination were obtained as 0.699, 0.322, and 60.6deg respectively. We also estimated the absolute parameters of the system using the Gaia DR3 parallax method. Therefore, the masses, radii, and luminosities have been determined to be M1=1.675, M2=1.171, R1=1.292, R2=1.097, L1=1.348, and L2=1.221. The orbital angular momentum (J0) of the CSS J003106.8+313347 illustrates that this system is located in a region of contact binaries. The positions of the primary and secondary components on the Hertzsprung-Russell (HR) diagram are depicted.