Related papers: Physical parameters of close binary systems: VIII
We presented the first photometric light curve solutions of four W Ursae Majoris (W UMa)-type contact binary systems. This investigation utilized photometric data from the Transiting Exoplanet Survey Satellite (TESS) and Gaia Data Release 3…
The observed masses, radii and temperatures of 60 medium- to long-period binaries, most of which contain a cool, evolved star and a hotter less-evolved one, are compared with theoretical models which include (a) core convective…
We carry out a re-analysis of the photometric data in Cousin RI bands which was taken under the Nainital Microlensing Survey during 1998 to 2002 with the aim to detect gravitational microlensing events in the direction of M31. Here, we do…
A new scenario for evolution of contact binaries is presented and discussed. Arguments are given that W UMa-type systems are formed from detached binaries which lose angular momentum via magnetized wind. This takes typically several Gyr.…
The CCD photometric data of the EW-type binary, II CMa, which is a contact star in the field of the middle-aged open cluster Berkeley 33, are presented. The complete R light curve was obtained. In the present paper, using the five CCD…
We investigate the properties of 367 ultra-short period binary candidates selected from 31,000 sources recently identified from Catalina Surveys data. Based on light curve morphology, along with WISE, SDSS and GALEX multi-colour photometry,…
Two CCD epochs of light minimum and a complete R light curve of SS Ari are presented. The light curve obtained in 2007 was analyzed with the 2003 version of the W-D code. It is shown that SS Ari is a shallow contact binary system with a…
We present the first light curve solution of 6 contact binary systems which are chosen from the ASAS catalog. The photometric elements and the estimated absolute parameters of all systems are obtained with the light curve analyses. We…
W UMa type binaries have two defining characteristics. These are (i) the effective temperatures of both components are very similar, and (ii) the secondary (currently less massive) component is overluminous for its current mass. We consider…
We used the newly commissioned 50 cm Binocular Network (50BiN) telescope at Qinghai Station of Purple Mountain Observatory (Chinese Academy of Sciences) to observe the old open cluster NGC 188 in V and R as part of a search for variable…
We survey a sample of 32 M5-M8 stars with distance < 40pc for companions with separations between 0.1 arcsec and 1.5 arcsec and with Delta m_i <5. We find five new VLM binaries with separations between 0.15 arcsec and 1.1 arcsec, including…
The most complete list of visual binary systems with known orbital elements is compiled. It is based on OARMAC and ORB6 data and contains 3139 orbits for 2278 pairs. A refined subset of high quality orbits with available distance was also…
The search-volume corrected period distribution of contact binaries of the W UMa type appears to reflect primarily the constant number ratio of ~1/500 to the number of stars along the Main Sequence; there exist no evidence for angular…
Overcontact binary stars are systems of two stars where the component stars are in contact with each other. This implies that they share a common envelope of gas. In this work we seek signatures of nonlinearity and chaos in these stars by…
It was recently demonstrated that contact binaries occur in globular clusters (GCs) only immediately below turn-off point and in the region of blue straggler stars (BSs). In addition, observations indicate that at least a significant…
Complex period variations of five W UMa type binaries (AB And, OO Aql, DK Cyg, V566 Oph, U Peg) were investigated by analyzing their O--C diagrams, and several common features were found. Four of the five systems show secular period…
We present a comprehensive study of the massive binary system HM1~8, based on multi-epoch high resolution spectroscopy, $V$-band photometry and archival X-ray data. Spectra from the OWN Survey, a high resolution optical monitoring of…
This study provides the first comprehensive analysis of eight total-eclipse W Ursae Majoris-type contact binary systems. Ground-based photometric multiband observations were conducted at a Mexican observatory, and new times of minima were…
We present a multi-band photometric analysis of CRTS J163819.6+03485, the first low mass ratio (LMR) contact binary system with a period under the contact binary (CB) period limit. The unprecedented combination of mass ratio and period…
Multi-color photometric light curves of NO Cam in $V$ $R_C$ and $I_C$ bands are obtained and analyzed simultaneously using the Wilson-Devinney (W-D) program. The solutions suggest that NO Cam is an A-subtype overcontact binary with its mass…