Study on the physical parameters of 18 contact binary stars

ABSTRACT We present the photometric light curve solutions of 18 W Ursae Majoris-type contact binary stars with orbital periods shorter than 0.5 d. This investigation utilized photometric data from the Transiting Exoplanet Survey Satellite, Gaia, and the All Sky Automated Survey for SuperNovae. We analysed light curves using the PHysics Of Eclipsing BinariEs Python code. Eleven of the targeted systems required the inclusion of a starspot on one of the components during the analysis process. The absolute parameters of the systems were estimated using the Gaia Data Release 3 (DR3) parallax method. Based on each component’s effective temperature and mass, we identified seven systems as A-subtypes and eleven as W-subtypes. We compared the results of our photometric mass ratio with a new method that estimates it using the third derivative of the light curve. The semimajor axes that were derived from the estimation of absolute parameters using the Gaia DR3 parallax method were discussed. The positions of the systems are illustrated on the logarithmic scales’ mass–luminosity and mass–radius diagrams compared to the theoretical terminal-age main sequence and zero-age main sequence lines. We generated a bibliographic compilation of orbital and stellar parameters, which includes 818 contact binary systems. Then, we updated the 2D empirical parameter relationships for the primary stars, including period–temperature, period–mass, period–radius, and period–luminosity, along with diagrams illustrating the positions of the target systems. This sample is accessible as a machine-readable file for the subsequent studies.