Related papers: Luminosity function of contact binaries based on t…

The first multicolor observations, and light curve solutions, of the eclipsing binary systems V1009~Per and CRTS~J031642.2+332639 are presented. Using the 2005 version of the Wilson-Devinney code, both systems are found to be W UMa contact…

In this study, all unpublished time series photometric data of BM UMa ($q \sim$ 2.0, P = 0.2712\,d) from available archives were re-investigated together with new data taken from the TNT-2.4m of the Thai National Observatory (TNO). Based on…

A sample of white dwarfs is selected from SDSS DR3 imaging data using their reduced proper motions, based on improved proper motions from SDSS plus USNO-B combined data. Numerous SDSS and followup spectra (Kilic et al. 2005) are used to…

The observations of W UMa type stars show a well-defined short-period limit of 0.22 d, which is equivalent to a lower mass limit of approximately 1 solar mass for the total binary mass. It is currently believed that cool contact binaries…

The period distribution of contact binaries exhibits a very sharp short period cut-off at 0.22 days. In order to provide valuable information on this short period limit, we observed ten totally eclipsing contact binaries with orbital…

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…

The first analysis of the photometric observation in BVR filters of a W UMa type binary system BQ Ari was performed. Light curve analysis was performed using Wilson-Devinney (W-D) code combined with a Monte Carlo (MC) simulation to…

This study presents new, high-quality, optical photometric observations of three W UMa type contact binaries. The analysis of the corresponding light curves is made using Djurasevic's inverse problem method. To explain the light curve…

The photometric and spectroscopic investigations of ten contact binaries were presented for the first time. It is discovered that the mass ratios of all the ten targets are smaller than 0.15, they are extremely low mass ratio contact…

CRTS J192848.7-404555 was recognised as a potential contact binary merger candidate on the basis of survey photometry analysis. We have carried out follow up ground based photometry of the system and show that at the recorded coordinates…

By analyzing two sets of complete $BVR_cI_c$ light curves of V342 UMa and three sets of complete $BVR_cI_c$ light curves of V509 Cam, we determined that the two systems are both W-subtype contact binaries and that V342 UMa shows a shallow…

We report on our analysis of HST/NICMOS snapshot high resolution images of 255 stars in 201 systems within ~10 parsecs of the Sun. Photometry was obtained through filters F110W, F180M, F207M, and F222M using NICMOS Camera 2. These filters…

We have obtained multi-epoch, high-resolution spectroscopy of 218 candidate low-mass stars and brown dwarfs in the young clusters around sigma Ori and lambda Ori. We find that 196 targets are cluster members based on their radial velocity,…

Parallaxes of W UMa stars in the Hipparcos catalogue have been analyzed. 31 W UMa stars, which have the most accurate parallaxes ($\sigma_{\pi}/\pi<0.15$) which are neither associated with a photometric tertiary nor with evidence of a…

With the development of wide-field surveys, a large amount of data on short-period W UMa contact binaries have been obtained. Continuous and uninterrupted light curves as well as high-resolution spectroscopic data are crucial in determining…

We have conducted a deep photometric survey of a 0.5 deg x 0.5 deg area of the Galactic Plane using the WFI instrument on the 2.2-m ESO telescope on La Silla, Chile. The dataset comprises a total of 267 R-band images, 204 from a 16 day…

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…

This work studies the significance of the lightcurve intrinsic variability in the numerical modeling of contact binaries. Using synthetic light curves we are showing that the starspot-based intrinsic variability increases the apparent mass…

We present the photometric analysis of six short-period systems (EI Oct, V336 TrA, NX Boo, V356 Boo, PS Boo, and V2282 Cyg). This is the first photometric analysis of these systems except for V336 TrA. Observations were conducted for 27…

The recently discovered eclipsing binary system TYC 2675-663-1 is a X-ray source, and shows properties in the optical that are similar to the W UMa systems, but are somewhat unusual compared to what is seen in other contact binary systems.…