Reanalyzing the Light Curves and Absolute Parameters of Twenty Contact Binary Stars Using TESS Data

TL;DR

This study reanalyzed twenty contact binary stars using TESS data, providing updated parameters and insights into their physical properties, orbital characteristics, and light curve asymmetries, contributing valuable data for theoretical models.

Contribution

It is the first to utilize TESS data for detailed analysis of these twenty contact binaries, updating their parameters and examining light curve asymmetries with starspot modeling.

Findings

Mass ratios ranged from 0.149 to 3.915.

Twelve systems showed the O'Connell effect.

Absolute parameters were estimated and systems plotted on multiple diagrams.

Abstract

Reanalyzing contact binaries with space-based photometric data and investigating possible parameter changes can yield accurate samples for theoretical studies. We investigated light curve solutions and fundamental parameters for twenty contact binary systems. The most recent Transiting Exoplanet Survey Satellite (TESS) data is used to analyze. The target systems in the investigation have an orbital period of less than 0.58 days. Light curve solutions were performed using the PHysics Of Eclipsing BinariEs (PHOEBE) Python code version 2.4.9. The results show that systems had various mass ratios from q=0.149 to q=3.915, fillout factors from f=0.072 to f=0.566, and inclinations from i=52.8deg to i=87.3deg. The effective temperature of the stars was less than 7016 K, which was expected given the features of most contact binary stars. Twelve of the target systems' light curves were asymmetrical in the maxima, showing the O'Connell effect, and a starspot was required for light curve solutions. The estimation of the absolute parameters of the binary systems was presented using the a-P empirical relationship and discussed. The orbital angular momentum (J_0) of the systems was calculated. The positions of the systems were also depicted on the M-L, M-R, q-L_ratio, M_tot-J_0, and T-M diagrams.