相关论文: The evolutionary status of W Ursae Majoris-type sy…

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…

Using Eggleton's stellar evolution code, we study the minimum mass ratio ($q_{\rm min}$) of W Ursae Majoris (W UMa) binaries that have different primary masses. It is found that the minimum mass ratio of W UMa binaries decreases with…

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…

Orbital angular momentum (Jo), systemic mass (M) and orbital period (P) distributions of chromospherically active binaries (CAB) and W Ursae Majoris (W UMa) systems were investigated. The diagrams of log Jo - log P, log M - log P and log…

Mass loss due to line-driven winds is central to our understanding of the evolution of massive stars. We extend the evolution models introduced in Paper I, where the mass loss recipe is based on the simultaneous calculation of the wind…

In this study, we determined the physical parameters of W UMa type contact binaries and its stability of mass transfer with different stellar mass ranges over a broad space by applying the basic dynamical evolution equations of the W UMa…

Results are presented on component masses and system angular momenta for over a hundred low-temperature contact binaries. It is found that the secondary components in close binary systems are very similar in mass. Our observational evidence…

Double-lined eclipsing binaries allow accurate and direct determination of fundamental parameters such as mass and radius for each component, and they provide important constraints on the stellar structure and evolution models. In this…

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…

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 study, a W Ursae Majoris (W UMa) type system LO Andromedae (LO And) was observed over nine nights at Durham to fully investigate its physical properties and update its stellar parameters. After obtaining the observational data in…

The period histograms of eclipsing binaries generated with ASAS data cannot only be interpreted by orbital evolution. The eclipse probabilities, selection effects and space distributions in the solar neighborhood should be considered before…

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.…

Evolution of Population I stars with initial masses from 70M_\odot to 130M_\odot is considered under various assumptions on the mass loss rate \dot M. The mass-luminosity relation of W-R stars is shown to be most sensitive to the mass loss…

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…

Here we present evolutionary models for a set of massive stars, introducing a new prescription for the mass-loss rate obtained from hydrodynamical calculations in which the wind velocity profile, $v(r)$, and the line-acceleration,…

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…

We present a MUSE and KMOS dynamical study 405 star-forming galaxies at redshift z=0.28-1.65 (median redshift z=0.84). Our sample are representative of star-forming, main-sequence galaxies, with star-formation rates of SFR=0.1-30Mo/yr and…

First, we review the main physical effects to be considered in the building of evolutionary models of rotating stars on the Upper Main-Sequence (MS). The internal rotation law evolves as a result of contraction and expansion, meridional…

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.…