Related papers: Horizontal Branch Stellar Evolution
The morphology of the Horizontal Branch (HB) in Globular Clusters (GC) is among the early evidences that they contain multiple populations of stars. Indeed, the location of each star along the HB depends both on its initial helium content…
We review recent developments in determining the evolution of magnetic massive OB stars. One of the important scientific questions is the completeness and the detection limits of contemporaneous spectropolarimetric surveys across the HR…
We present a detailed analysis of the "second-parameter pair" of globular clusters M3 (NGC 5272) and Palomar 3. Our main results can be summarized as follows: i) The horizontal-branch (HB) morphology of M3 is significantly bluer in its…
Stellar rotation significantly shapes the evolution of massive stars, yet the interplay of mass and metallicity remains elusive, limiting our capacity to construct accurate stellar evolution models and to better estimate the impact of…
Envelope stripping, whether through single-star wind mass loss or binary mass transfer, is a key evolutionary pathway for the formation of classical Wolf-Rayet stars and lower-mass stripped helium (He) stars. However, to study the evolution…
Binary evolution is investigated as the source for the extreme horizontal branch (EHB) stars in the old and metal rich open cluster NGC~6791. Employing an updated version of our binary stellar evolution code we demonstrate that EHB stars…
The impact of metallicity on the mass-loss rate from red giant branch (RGB) stars is studied through its effect on the parameters of horizontal branch (HB) stars. The scaling factors from Reimers (1975) and Schroder & Cuntz (2005) are…
We present a study of Far Ultraviolet (FUV) bright horizontal branch (HB) stars to understand the peculiarities seen in the HB sequence of the Globular Cluster NGC 1851, using ground and space based multi-wavelength data. Optical and UV…
A review is presented of some of the ingredients, assumptions and techniques that are used in the computation of the structure and evolution of low-mass stars. Emphasis is placed on several ingredients which are still subject to…
During the last decade, the understanding of fine features of the structure and evolution of stars has become possible as a result of enormous progress made in the acquisition of high-quality observational and experimental data and of new…
The formation of hot subdwarf stars is still unclear. Both single-star and binary scenarios have been proposed to explain the properties of these evolved stars situated at the extreme blue end of the horizontal branch. The observational…
Mass loss and axial rotation are playing key roles in shaping the evolution of massive stars. They affect the tracks in the HR diagram, the lifetimes, the surface abundances, the hardness of the radiation field, the chemical yields, the…
Studies of the observed characteristics of black-hole (BH) X-ray binaries can be provide us with valuable information about the process of BH formation. In this paper I address some of the aspects of our current understanding of BH…
Enhancement and spread of helium among globular cluster stars have been recently suggested as a way to explain the horizontal branch blue tails, in those clusters which show a primordial spread in the abundances of CNO and other elements…
We present a detailed abundance analysis and atmospheric parameters of 76 stars from a survey to identify field Galactic red horizontal-branch (RHB) stars. High-resolution echelle spectra (R\simeq60,000, S/N>=100) were obtained with 2.7 m…
The presence of an extended blue horizontal branch (HB) in a stellar population is known to affect the age inferred from spectral fitting to stellar population synthesis models. However, most population synthesis models still rely on…
We present a grid of evolutionary calculations for metal-poor low-mass stars for a variety of initial helium and metal abundances. The intention is mainly to provide a database for deriving directly stellar ages of halo and globular cluster…
We present a brief overview of the theory of stellar winds with a strong emphasis on the radiation-driven outflows from massive stars. The resulting implications for the evolution and fate of massive stars are also discussed. Furthermore,…
We present a new set of horizontal-branch (HB) models computed with the MESA stellar evolution code. The models adopt $\alpha$-enhanced \cite{ags09} metals mixtures and include the gravitational settling of He. They are used in our HB…
The connection between AGB evolution of stellar populations and infrared vs. ultraviolet properties of the parent galaxies is reviewed relying on the updated lookout provided by population-synthesis theory. In particular, planetary-nebula…