相关论文: Mass-luminosity relation and pulsational propertie…

Grids of models of massive stars ($M \ge$ 20 $M_\odot$) with rotation are computed for metallicities $Z$ ranging from that of the Small Magellanic Cloud (SMC) to that of the Galactic Centre. The hydrostatic effects of rotation, the…

We examine the properties of Wolf--Rayet (WR) stars predicted by models of rotating stars taking account of the new mass loss rates for O--type stars and WR stars (Vink et al. \cite{Vink00}, \cite{Vink01}; Nugis & Lamers \cite{NuLa00}) and…

Wolf-Rayet (WR) stars near solar metallicity are believed to be driven by radiation pressure on the UV spectral lines of metal ions. As the metallicity decreases so does the line opacity, therefore the mass-loss rate. However, since the…

Classical Wolf-Rayet (WR) stars mark an important stage in the late evolution of massive stars. As hydrogen-poor massive stars, these objects have lost their outer layers, while still losing further mass through strong winds indicated by…

Wolf-Rayet (WR) stars are the most advanced stage in the evolution of the most massive stars. The strong feedback provided by these objects and their subsequent supernova (SN) explosions are decisive for a variety of astrophysical topics…

Stellar evolution calculations for population II stars with initial composition $Y_0=0.25$, $Z_0=10^{-3}$ and the initial stellar mass $M_0 = 0.82M_\odot$ were carried out from the main sequence to the white dwarf stage. Twelve AGB and…

The first stars are assumed to be predominantly massive. Although, due to the low initial abundances of heavy elements the line-driven stellar winds are supposed to be inefficient in the first stars, these stars may loose a significant…

(abridged) The strong winds of Wolf-Rayet (WR) stars are important for the mechanical and chemical feedback of the most massive stars and determine whether they end their lives as neutron stars or black holes. In this work we investigate…

Numerical simulations of the evolution of strange-mode instabilities into the non-linear regime have been performed for a wide range of stellar parameters for Wolf-Rayet stars. It has been shown that the Wolf-Rayet models reach radial…

Wolf-Rayet (WR) stars have a severe impact on their environments owing to their strong ionizing radiation fields and powerful stellar winds. Since these winds are considered to be driven by radiation pressure, it is theoretically expected…

CONTEXT: The mass loss of He-burning stars, which are partially or completely stripped of their outer hydrogen envelope, is a catalyst of the cosmic matter cycle and decisive ingredient of massive star evolution. Yet, its theoretical…

We present evolutionary models of zero-metallicity very massive objects, with initial masses in the range 120 Msun -- 1000 Msun, covering their quiescent evolution up to central carbon ignition. In the attempt of exploring the possible…

The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, due to the extreme physical conditions within their line and continuum forming regions. Recently, model atmosphere studies have…

We have performed a pilot study of mass loss predictions for late-type Wolf-Rayet (WR) stars as a function of metal abundance, over a range between 10^{-5} < (Z/Zsun) < 10. We find that the winds of nitrogen-rich Wolf-Rayet stars are…

The mass-loss rates of massive helium stars are one of the major uncertainties in modern astrophysics. Regardless of whether they were stripped by a binary companion or managed to peel off their outer layers by themselves, the influence and…

Vigorous mass loss in the classical Wolf-Rayet (WR) phase is important for the late evolution and final fate of massive stars. We develop spherically symmetric time-dependent and steady-state hydrodynamical models of the radiation-driven…

Aims: Recent theoretical predictions for the winds of Wolf-Rayet stars indicate that their mass-loss rates scale with the initial stellar metallicity in the local Universe.We aim to investigate how this predicted dependence affects the…

Recently the observationally derived stellar-wind mass-loss rates for Wolf-Rayet stars, or massive naked helium stars, have been revised downwards by a substantial amount. We present evolutionary calculations of helium stars incorporating…

[Abridged] Context: Radiation-driven mass loss plays a key role in the life-cycles of massive stars. However, basic predictions of such mass loss still suffer from significant quantitative uncertainties. Aims: We develop new…

Wolf-Rayet (WR) stars are massive stars that have lost most or all of their hydrogen via powerful stellar winds. Recent observations have indicated that hydrogen-free WR stars have cooler temperatures than those predicted by current…