Physical properties and period changes of binary systems NSVS 14256825, TW Cas and IM Aur

Abstract

This research presents a new analysis of the photometric data of NSVS 14256825 (sdOB+dM) eclipsing binary system with a short period 0.11374230 days and combined photometric light curves and radial velocity studies of TW Cas and IM Aur, Algol-type eclipsing binaries with orbital period 1.4283 days and 1.2473 days, respectively. In this study, physical properties and period variations of the binaries are revealed. Simultaneously modeling of the photometric and spectroscopic data are conducted using the PHysics Of Eclipse BinariES (PHOEBE) Python code package. The best-fitting of geometrical and physical parameters are calculated from the Markov Chain Monte Carlo (MCMC) method. The period change of (O-C) diagrams of three systems indicated variability which causes by third body perturbation. In this work, the physical parameters of NSVS 14256825's third body are obtained.