Light Curve Analysis of the AP Dor Binary System using Ground-based and TESS Observations

Abstract

The short-period eclipsing binary AP Dor's first in-depth and multiband photometric solutions are presented. We made use of our eight nights of ground-based opportunity at a southern hemisphere observatory, and twelve sectors of TESS observations. We extracted eight and 1322 minima from our observations and TESS, respectively. We suggest a new linear ephemeris based on the trend of orbital period variations using the Markov chain Monte Carlo (MCMC) approach. The PHysics Of Eclipsing BinariEs (PHOEBE) Python code and the MCMC approach were utilized for the light curve analysis. This system did not require a starspot for the light curve solutions. We calculated the absolute parameters of the system by applying the Gaia DR3 parallax method. The orbital angular momentum (J0) of AP Dor indicates that this system is located in a region corresponding to contact binaries. According to our results, this system is an overcontact binary system with a mass ratio of 0.584, a fillout factor of 48%, and an inclination of 53°. The positions of component stars in the AP Dor system on the Hertzsprung–Russell diagram are found.