An investigation of low-mass-ratio EW systems from the Catalina Sky Survey.

Abstract

We have conducted a survey of overcontact binary systems (EW) with mass ratio = 0.25 from the Catalina Sky Survey (CSS) that are considered strong merger candidates and are probable progenitors of FK Com-type stars and blue stragglers. The discovery of such extreme mass ratio overcontact binaries is vital to resolve the critical mass ratio ambiguity to merge, the mass loss process, and to refine the current theoretical models. So far only a few tens of such systems have been identified. To increase this sample, we selected and derived the physical parameters (mass, temperature and radius ratios, inclination and fill-out factor, along with their respective uncertainties) of 92 newly discovered totally eclipsing low-mass-ratio (LMR) EW systems based on their VCSS light curves, using PHOEBE-0.31a scripter and Monte Carlo methods.