Mass-transfer properties of overcontact systems in the Kepler eclipsing binary catalog

Abstract

We selected mass-transferring binary candidates from the catalog of Kepler eclipsing binary stars and investigated the dependence of the mass-transfer rate on several astrophysical quantities, including orbital period, semi-major axis, mass ratio, fill-out factor, temperature, and mass. We selected these candidates using $O-C$ diagrams and calculated their mass-transfer rates. Primary masses were obtained from the mass--temperature relation, and the temperatures of the component stars were extracted from a catalog of temperatures for Kepler eclipsing binary stars. The mass-transfer rates of overcontact systems have associations with astrophysical quantities that seem to differ from those of semi-detached or detached systems. These associations indicate that mass exchange from more- to less-massive components (from less- to more-massive components) generally becomes rapid (slow) as the mass exchange evolves. However, for mass exchange from more- to less-massive components, this tendency is not reasonable for binaries with a short period ($P<0.4$ d) and low mass ($M_1<1.2$ M${}_{\odot }$) because the correlations of these binaries are opposite to those of binaries with long period and high mass. These different correlations likely arise from differences in correlation between subtypes of W UMa systems (i.e., W- and A-types). Alternatively, when mass exchange from more- to less-massive components reoccurs after a mass-ratio reversal, its properties may differ from those of the first mass exchange.

12 pages, 9 figures, Accepted for publication in PASJ

References in corpus (5)

• Tertiary companions to close spectroscopic binaries
• Dynamical evolution of active detached binaries on log Jo - log M diagram and contact binary formation
• Contact binaries with additional components. III. The adaptive optics detections
• The short period end of the contact binary period distribution based on the All Sky Automated Survey (ASAS)
• Masses and angular momenta of contact binary stars

Cited by in corpus (5)

• Systematic search for stellar pulsators in the eclipsing binaries observed by Kepler
• Investigation of the Orbital Period and Mass Relations for W UMa-type Contact Systems
• CoBiToM Project -- II: Evolution of contact binary systems close to the orbital period cut-off
• Case AD, AR, and AS binary evolution and their possible connections with W UMa binaries
• Characteristics of Kepler Eclipsing Binaries Displaying a Significant O'Connell Effect