Related papers: Evolution of the Most Massive Stars
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…
We consider whether the maximum mass of first stars is imposed by the protostellar spin, i.e., by the so-called $\Omega\Gamma$-limit, which requires the sum of the radiation and centrifugal forces at the stellar surface be smaller than the…
Several properties of massive stars with large effects of rotation and radiation are studied. We show that there are 2 roots for the equation giving the rotational velocities at break-up: 1) The usual solution, which is shown to apply when…
New constraints on stellar models are provided by large surveys of massive stars, interferometric observations and asteroseismology. After a review of the main results so far obtained, we present new results from rotating models and discuss…
We explore the role of the modified Eddington limit due to rapid rotation (the so-called $\Omega\Gamma-$limit) in the formation of Population III stars. We performed one-dimensional stellar evolution simulations of mass-accreting…
We give a brief overview of where we stand with respect to some old and new questions bearing on how massive stars evolve and end their lifetime. We focus on the following key points that are further discussed by other contributions during…
We review potential mass-loss mechanisms in the various evolutionary stages of massive stars, from the well-known line-driven winds of O-stars and BA-supergiants to the less-understood winds from Red Supergiants. We discuss optically thick…
We summarize the present status of the predictions of massive star models for the evolution of their surface properties. After discussing luminosity, temperature and chemical composition, we focus on the question whether massive stars may…
After presenting a short history of gamma-ray burst (GRB) studies, we discuss the current constraints on GRB models which follows from astronomical observations. We concentrate on the energetics of the GRBs with known redshifts and the…
We use contemporary evolutionary models for Very Massive Stars (VMS) to assess whether the Eddington limit constrains the upper stellar mass limit. We also consider the interplay between mass and age for the wind properties and spectral…
This paper reviews the physics of stars, the type, structure, evolution and stability. Simple thermodynamics and statistical mechanics are used to show the inner working of white dwarf and neutron stars. The major concentration of the paper…
Rotation appears as a dominant effect in massive star evolution. It largely affects all the model outputs: inner structure, tracks, lifetimes, isochrones, surface compositions, blue to red supergiant ratios, etc. At lower metallicities, the…
We consider some aspects of the evolution of massive stars which can only be elucidated by means of "indirect" observations, i.e. measurements of the effects of massive stars on their environments. We discuss in detail the early evolution…
The Humphreys-Davidson (HD) limit sets the boundary between evolutionary channels of massive stars that either end their lives as red supergiants (RSGs) or as the hotter blue supergiants (BSGs) and Wolf-Rayet stars. Mixing in the envelopes…
Gamma ray bursts (GRBs) are the most luminous physical phenomena in the universe. The relativistic effect on the blast wave associated with the GRB introduces the gamma factor. Here we put an upper limit on the gamma factor via constraints…
The consideration of the N-body gravitational problem equations can give to us some class of boundary-value problems defined on the "beem's" construction. One can considere it as weak or so-called finite element method's approximation with…
One of the key questions in Astrophysics concerns the issue of whether there exists an upper-mass limit to stars, and if so, what physical mechanism sets this limit, which might also determine if the upper-mass limit is metallicity (Z)…
Rotation has a number of important effects on the evolution of stars. It decreases the surface gravity, causes enhanced mass loss and leads to surface abundance anomalies of various chemical isotopes. We have adapted the Cambridge stellar…
In discussing open question in the field of massive stars, I consider their evolution from birth to death. After touching upon massive star formation, which may be bi-modal and not lead to a zero-age main sequence at the highest masses, I…
The holographic upper bound on entropy is applied to the gravitational action associated with the non-relativistic contraction of a nebula. A critical radius is identified, as a function of the initial radius and mass, for which the number…