Related papers: Early-type contact systems in the LMC MACHO databa…

We have analysed publicly available MACHO observations of 6833 variable stars in the Large Magellanic Cloud, classified as eclipsing binaries. After finding that a significant fraction of the sample was misclassified, we redetermined…

We present an extensive analysis of new light and radial-velocity (RV) curves, as well as high-quality broadening-function (BF) profiles of twelve binary systems for which a contact configuration with large temperature differencies between…

We have attempted to establish an observational evidence for presence of distant companions which may have acquired and/or absorbed the angular momentum during evolution of multiple systems thus facilitating or enabling formation of contact…

This study broadens our comprehensive investigation of total-eclipse W Ursae Majoris-type contact binaries by analyzing eight additional systems, continuing our previous research. Multiband $BVR_cI_c$ photometric data were obtained at an…

Luminous X-ray binaries (>1E34 erg/s, LMXBs) have a neutron star or black hole primary, and in globular clusters, most of these close binaries are expected to be have evolved from wider binaries through dynamical interactions with other…

Light curves of the contact systems visible in the direction of Baade's Window have been analyzed using the first coefficients of the Fourier representation. The results confirm that the geometric contact between components is usually weak.…

TX Cnc is a member of the young open cluster NGC 2632. In the present paper, four CCD epochs of light minimum and a complete V light curve of TX Cnc are presented. A period investigation based on all available photoelectric or CCD data…

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…

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 last comprehensive catalogue of high-mass X-ray binaries in the Small Magellanic Cloud (SMC) was published about ten years ago. Since then new such systems were discovered, mainly by X-ray observations with Chandra and XMM-Newton. For…

This study continues our in-depth investigation of total-eclipse W Ursae Majoris-type contact binaries by analyzing eight new systems, complementing our previous work. Multiband $BVR_cI_c$ photometric data were acquired through ground-based…

77 W~UMa-type systems to $I=18$ mag in one of the 21 fields of OGLE have been assessed in terms of utility for extraction of astrophysical information from time-independent data such as colors, periods, maximum magnitudes, and variability…

We present evolutionary calculations for 74 close binaries systems with initial primary masses in the range 12...25 M_sun, and initial secondary masses between 6 and 24 M_sun. The initial periods were chosen such that mass overflow starts…

We present a study on low-mass contact binaries (LMCB) with orbital periods shorter than 0.3 days and total mass lower than about 1.4 solar mass. We show that such systems have a long pre-contact phase, which lasts for 8-9 Gyrs, while the…

A modification to the absolute magnitude calibration for W~UMa-type systems, taking into account differences in metal abundances, is derived on the basis of contact binary systems recently discovered in metal-poor clusters. A preliminary…

(Abridged) Chandra and Hubble ACS observations of 11 early-type galaxies probe the low-mass X-ray binary (LMXB) - globular cluster (GC) connection. We explore the optical properties of 270 GCs with LMXBs and 6,488 GCs without LMXBs. More…

We present the photometric analysis of three ultra-short period total eclipsing binaries in contact configuration, CRTS_J172718.0+431624, OGLE-BLG-ECL-000104, and OGLE-BLG-ECL-000012, mined from massive astronomical surveys. Using the…

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.…

We report the discovery of 73 double-mode RR Lyrae (RRd) stars in fields near the bar of the LMC. The stars are detected among the MACHO database of short-period variables that currently contains about 7900 RR Lyrae stars. Fundamental…

The Magellanic Clouds host a large population of high-mass X-ray binary (HMXB) systems, but although the Large Magellanic Cloud (LMC) is an order of magnitude more massive than the Small Magellanic Cloud, significantly fewer HMXBs are…