Related papers: A model of AW UMa
Extreme mass-ratio contact binaries with a high degree of overcontact may be in the late evolutionary stages of the contact phase. Detailed photometric analyses and orbital period studies of those systems can provide invaluable information…
Ultra-short orbital period contact binaries (Porb < 0.26 d) host some of the smallest and least massive stars. These systems are faint and rare, and it is believed that they have reached a contact configuration after several Gyrs of…
Only a few well characterized very low-mass M dwarfs are known today. Our understanding of M dwarfs is vital as these are the most common stars in our solar neighborhood. We aim to characterize the properties of a rare F+dM stellar system…
ZZ UMa is a detached eclipsing binary with an orbital period of 2.299 d that shows total eclipses and starspot activity. We used five sectors of light curves from the Transiting Exoplanet Survey Satellite (TESS) and two published sets of…
We report the detection of sixteen binary systems from the Anglo-Australian Planet Search. Solutions to the radial velocity data indicate that the stars have companions orbiting with a wide range of masses, eccentricities and periods. Three…
The four-color ($B$ $V$ $R_c$ $I_c$) light curves of V776 Cas are presented and analyzed using the Wilson-Devinney (W-D) method. It is discovered that V776 Cas is an early F-type (F2V) overcontact binary with a very high contact degree ($…
High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429 Cam), while the others are W-type contact ones. By analyzing the times…
We selected mass-transferring binary candidates from the catalog of Kepler eclipsing binary stars and investigated the dependence of the mass-transfer rate on several astrophysical quantities, including orbital period, semi-major axis, mass…
In this study, we present photometric and spectroscopic variations of the extremely small mass ratio ($q\simeq 0.1$) late-type contact binary system \astrobj{V1191 Cyg}. The parameters for the hot and cooler companions have been determined…
We present the revised and high quality CCD time series observations in 2017 and 2018 of the W UMa-type contact binary BH~Cas. The combination of our new determinations of minimum times and those collected from the literatures reveal a…
The luminosity function for contact binary stars of the W~UMa-type is evaluated on the basis of the ASAS photometric project covering all stars south of delta= +28 within a magnitude range 8<V<13. Lack of colour indices enforced a…
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}.…
A comprehensive evolution study was conducted on a carefully selected sample of near-contact binaries (NCBs) with more massive components filling the Roche lobes, utilizing the best-known basic parameters and indications of ongoing mass…
Wide binary stars are important for testing alternative models of gravitation in the weak-field regime and understanding the statistical outcomes of dynamical interactions in the general Galactic field. The Gaia mission's collection of…
Binary stars and higher-order multiple systems are an ubiquitous outcome of star formation, especially as the system mass increases. The companion mass-ratio distribution is a unique probe into the conditions of the collapsing cloud core…
Massive stars that lose their hydrogen-rich envelope down to a few tenths of a solar mass explode as extended type IIb supernovae, an intriguing subtype that links the hydrogen-rich type II supernovae with the hydrogen-poor type Ib and Ic.…
Both high precision CCD photometric and H$alpha$ line studies are presented for an overcontact binary ASAS J082243+1927.0. The light curve exhibits a total eclipse at secondary minima along with an O'Connell effect. The light curve was…
Using high resolution near-infrared spectroscopy with the Keck telescope, we have detected the radial velocity signatures of the cool secondary components in four optically identified pre-main-sequence, single-lined spectroscopic binaries.…
In some semi-detached binary systems, the donor star may transfer mass to the companion at a very high rate. We propose that, at sufficiently high mass-transfer rates such that the accretion disk around the companion becomes geometrically…
CONTEXT: Accurate physical properties of eclipsing stars provide important constraints on models of stellar structure and evolution, especially when combined with spectroscopic information on their chemical composition. Empirical…