Photometric Study of Three Short-Period Eclipsing Binaries from the ASAS Catalogue

Abstract

We carried out high-precision photometric observations of three eclipsing ultrashort-period contact binaries (USPCBs). Theoretical models were fitted to the light-curves by means of the Wilson-Devinney code. The solutions suggest that the three targets have evolved to a contact phase. The photometric results are as follows: a) 1SWASP J030749.87−365201.7, q = 0.439 ± 0.003, f = 0.0±3.6 %; b) 1SWASP J213252.93−441822.6, q = 0.560±0.003, f = 14.2±1.9 %; c) 1SWASP J200059.78+054408.9, q = 0.436 ± 0.008, f = 58.4 ± 1.8 %. The light curves show O'Connell effects, which can be modeled by assumed cool spots. The cool spots models are strongly supported by the night-tonight variations in the I-band light curves of 1SWASP J030749.87−365201.7. For a comparative study, we collected the whole set of 28 well-studied USPCBs with P < 0.24 day. Thus, we found that most of them (17 of 28) are in shallow contact (i.e. fill-out factors f < 20 %). Only 4 USPCBs have deep fill-out factors (i.e. f > 50 %). Generally, contact binaries with deep fill-out factors are going to merge, but it

Characteristics of Kepler Eclipsing Binaries Displaying a Significant O’Connell Effect

“…For comparison, the All-Sky Automated Survey (ASAS) found 11,099 eclipsing binaries south of decl. +28° (Obu & Okeke 2013), while the Optical Gravitational Lensing Experiment survey found over 425,000 eclipsing binaries toward the galactic bulge (Soszyński et al 2016). The KEBC also contains eclipsing binaries with many different characteristics and allows us to study a complete, statistically significant sample.…”