Related papers: Physical parameters of W UMa type contact binaries…
The structure and evolution of low mass W UMa type contact binaries are discussed by employing Eggleton's stellar evolution code. Assuming that these systems completely satisfy Roche geometry, we calculate the relative radii of both…
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 presented the first high-precision, detailed photometric analysis of four W Ursae Majoris (W UMa)-type contact binaries, Linear 10772300, Linear 11150338, Linear 20372537 and DM Cir. In addition to ground-based multiband photometric…
Recently, our understanding of the origin of W UMa-type contact binaries has become clearer. Initial masses of their components were successfully estimated by Y{\i}ld{\i}z and Do\u{g}an using a new method mainly based on observational…
Contact binaries are close binary systems in which both components fill their inner Roche lobes so that the stars are in direct contact and in potential mass and energy exchange. The most common such systems of low-mass are the so-called W…
Multiband photometric investigations for eight binary systems of the W Ursae Majoris (W UMa)-type are presented. Six systems are presented for the first time to analyze their light curves. All the analyzed systems have a temperature below…
The energy transfer of W UMa contact binaries and its effects on the secondary in W UMa contact binaries are investigated. Relations are given between the mass ratio (q) and the relative energy transfer rates, i.e. U1, the ratio of the…
In this work, we present a detailed investigation of five contact binary systems of the W Ursae Majoris (W UMa) type. Multiband photometric observations were conducted using ground-based telescopes in both the northern and southern…
In a preceding paper, using Eggleton's evolution code we have discussed the structure and evolution of low-mass W UMa type contact binaries without angular momentum loss (AML). The models exhibit cyclic behavior about a state of marginal…
Despite being the most abundant (by space density) of interacting binary stars, W Ursae Majoris (W UMa) stars are not understood structurally. Their stellar components are in physical contact, and share a common convective envelope.…
High resolution spectroscopic observations of AW UMa, obtained on three consecutive nights with the median time resolution of 2.1 minutes, have been analyzed using the Broadening Functions method in the spectral window Doppler images of the…
We use extensive model grids to estimate the global parameters of four partially-eclipsing W UMa contact binaries near the period cutoff. All four systems consist of K-type main sequence primaries and M-type secondaries that appear…
We present new, high-quality multicolor observations of four recently discovered contact binaries: 1SWASP J064501.21+342154.9, 1SWASP J155822.10-025604.8, 1SWASP J212808.86+151622.0, and UCAC4 436-062932, and analyze their light curves to…
New relationships between the orbital period and some parameters of W Ursae Majoris (W UMa) type systems are presented in this study. To investigate the relationships, we calculated the absolute parameters of a sample of 118 systems. For…
Various scenarios of contact binary evolution have been proposed in the past, giving hints of (sometimes contradictory) evolutionary sequence connecting A-type and W-type systems. As the components of close detached binaries approach each…
This paper presents the results of a combined spectroscopic and photometric study of 20 contact binary systems: HV Aqr, OO Aql, FI Boo, TX Cnc, OT Cnc, EE Cet, RWCom, KR Com, V401 Cyg, V345 Gem, AK Her, V502 Oph, V566 Oph, V2612 Oph, V1363…
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.…
We present the multi-band photometric and low-resolution spectroscopic analysis of four W Ursae Majoris eclipsing binaries (EWs) - J080510.1+141528 (hereinafter as J0805a), J080516.3+143138 (hereinafter as J0805b), J143358.7+053953…
We performed a comprehensive analysis of 27 short period contact binary systems for which no light curve analysis had previously been reported. Photometric time-series data from the TESS mission were used in this analysis. The observational…
Theoretical study indicates that a contact binary system would merge into a rapidly rotating single star due to tidal instability when the spin angular momentum of the system is more than a third of its orbital angular momentum. Assuming…