Related papers: Structure and evolution of pulsating hot subdwarfs
Most of low- and intermediate-mass stars that populate the Universe will end their lives as white dwarf stars. These ancient stellar remnants have encrypted inside a precious record of the evolutionary history of the progenitor stars,…
Correlations between stellar kinematics and chemical abundances are fossil evidence for evolutionary connections between Galactic structural components. Extensive stellar surveys show that the only tolerably clear distinction between…
The evolutionary calculations for population I stars with masses on the main sequence 5 M_\odot <= M_0 <= 6.1 M_\odot and initial fractional abundances of helium Y_0=0.28 and heavier elements Z_0=0.02 were carried out to the stage of…
We investigate the evolutionary behavior of stellar structures with metallicity Z=0.04 in order to disclose theoretical expectations for both evolutionary and pulsational behaviors of Super-Metal-Rich (SMR) objects, which are found in the…
Rotation in massive stars has been studied on the main sequence and during helium burning for decades, but only recently have realistic numerical simulations followed the transport of angular momentum that occurs during more advanced stages…
A young open cluster is a 2-phase system: an ensemble of stars move in a gaseous medium (the mother molecular cloud). The dynamics and thermodynamics of the system, and so its evolution and final fate (is it stable or unstable?), strongly…
The origin of hot subdwarf B stars (sdBs) is still unclear. About half of the known sdBs are in close binary systems for which common envelope ejection is the most likely formation channel. Little is known about this dynamic phase of binary…
Most stars are members of binaries, and the evolution of a star in a close binary system differs from that of an ioslated star due to the proximity of its companion star. The components in a binary system interact in many ways and binary…
Hot subdwarfs represent a poorly understood late phase of stellar evolution. While binary evolution plays an important role for B-subdwarfs (sdB), the origin of the He dominated O-subdwarfs (He-sdO) is unknown. We search for chemical…
Motivated by the recent detection of single and binary He-core white dwarfs in metal-rich clusters, we present a full set of evolutionary calculations and colors appropriate for the study of such white dwarfs. The paper is also aimed at…
Global stellar oscillations probe the internal structure of stars. In low- to intermediate-mass red giants, these oscillations provide signatures from both the outer regions of the star as well as from the core. These signatures are…
Two of the possibilities for the formation of low-mass ($M_{\star}\lesssim 0.5\,M_{\odot}$) hydrogen-deficient white dwarfs are the occurrence of a very-late thermal pulse after the asymptotic giant-branch phase or a late helium-flash onset…
As they evolve, white dwarfs undergo major changes in surface composition, a phenomenon known as spectral evolution. In particular, some stars enter the cooling sequence with helium atmospheres (type DO) but eventually develop hydrogen…
We revisit the evolutionary scenario for Hot Flasher low-mass structures, where mass loss delays the He flash till the initial phases of their White Dwarf cooling sequence. Our aim has been to test the theoretical results vis-a-vis…
Massive stars evolve toward the catastrophic collapse of their innermost core, producing core-collapse supernova (SN) explosions as the end products. White dwarfs, formed through evolution of the less massive stars, also explode as…
The recent distance determinations by HIPPARCOS have allowed to locate very precisely a reasonable set of subdwarfs in the HR diagram. A detailed comparison with evolutionary models is now possible and it has been recently claimed that the…
We examine the evolution of low-mass star and brown dwarf eclipsing binaries. These objects are rapid rotators and are believed to shelter large magnetic fields. We suggest that reduced convective efficiency, due to fast rotation and large…
Ultra-faint dwarf galaxies serve as powerful testing grounds for wave dark matter models through dynamical stellar heating. Previous simulation-based work derived a lower bound on the fuzzy dark matter particle mass using a diffusion…
We present an extensive survey for rapid pulsators among Extreme Horizontal Branch (EHB) stars in omega Cen. The observations performed consist of nearly 100 hours of time-series photometry, as well as low-resolution spectroscopy. We…
The purpose of this work is to explore the evolution of helium-core white dwarf stars in a self-consistent way with the predictions of detailed non-gray model atmospheres and element diffusion. To this end, we consider helium-core white…