A CCD photometric study of the late type contact binary EK Comae Berenices

Abstract

We present CCD photometric observations of the W UMa type contact binary EK Comae Berenices using the 2 metre telescope of $IUCAA$ Girawali Observatory, India. The star was classified as a W UMa type binary of subtype-W by \citet{sam1996}. The new V band photometric observations of the star reveal that shape of the light curve has changed significantly from the one observed by \citet{sam1996}. A detailed analysis of the light curve obtained from the high-precision CCD photometric observations of the star indicates that EK Comae Berenices is not a W-type but an A-type totally eclipsing W UMa contact binary. The photometric mass ratio is determined to be 0.349 $\pm$ 0.005. A temperature difference of $\Delta T=141\pm 10$ K between the components and an orbital inclination of $i{[}^o]=89.800\pm 0.075$ were obtained for the binary system. Absolute values of masses, radii and luminosities are estimated by means of the standard mass-luminosity relation for zero age main-sequence stars. The star shows O'Connell effect, asymmetries in the light curve shape around the primary and secondary maximum. The observed O'Connell effect is explained by the presence of a hot spot on the primary component.

26 pages, 9 figures, 5 tables. Accepted for publication in New Astronomy

References in corpus (3)

• A Computational Guide to Physics of Eclipsing Binaries. Paper I. Demonstrations and Perspectives
• On the properties of contact binary stars
• Time-Series Photometry of M67: W UMa Systems, Blue Stragglers, and Related Systems

Cited by in corpus (3)

• Comparative study of TESS photometry and radial velocities on six early K-type contact binaries with similar periods around 0.268 days
• Light curve modeling of eclipsing binaries towards the constellation of Carina
• Physical properties of three short period close binaries: kic 2715417, kic 6050116 and kic 6287172