Related papers: Entropy Production and Luminosity-Effective Temper…
Methods to determine abundances of the elements in the atmospheres of F, G, and K stars with precisions of 0.01-0.03 dex are reviewed. Such high-precision stellar abundances have led to the discovery of unexpected phenomena and relations…
We consider a generic classical many particle system described by an autonomous Hamiltonian $H(x^{_1},...,x^{_{N+2}})$ which, in addition, has a conserved quantity $V(x^{_1},...,x^{_{N+2}})=v$, so that the Poisson bracket $\{H,V \}$…
We derive the stellar parameters of a sample of Galactic early-O type stars by analysing their UV and Far-UV spectra from FUSE (905-1187A), IUE, HST-STIS and ORFEUS (1200-2000A). The data have been modeled with spherical, hydrodynamic,…
New determinations of effective temperatures of 23 magnetic, chemically peculiar (mCP) stars were obtained from a fit of metal enhanced model atmospheres to the observed spectral energy distributions (SED) from UV to red. The…
During the past decade, several studies reported a correlation between chemical abundances of stars and condensation temperature (also known as Tc trend). However, the real astrophysical nature of this correlation is still debated. The main…
In this paper, we show how the MEP hypothesis may be used to build simple climate models without representing explicitly the energy transport by the atmosphere. The purpose is twofold. First, we assess the performance of the MEP hypothesis…
We select 947 star-forming galaxies from SDSS-DR7 with [O~{\sc iii}]$\lambda$4363 emission lines detected at a signal-to-noise {ratio }larger than 5$\sigma$. Their electron temperatures and direct oxygen abundances are {then }determined.…
Certain thermal non-equilibrium situations, outside of the astrophysical realm, suggest that entropy production extrema, instead of entropy extrema, are related to stationary states. In an effort to better understand the evolution of…
A most desirable feature of a standard candle to estimate astronomical distances is robustness against changes in metallicity and age. It is argued that the radii of main sequence stars with spectral types from solar to A0 show predictable…
The electron capture process plays an important role in the evolution of the core collapse of a massive star that precedes the supernova explosion. In this study, the electron capture on nuclei in stellar environment is described in the…
Entropy production (EP) is known as a fundamental quantity for measuring the irreversibility of processes in thermal equilibrium and states far from equilibrium. In stochastic thermodynamics, the EP becomes more visible in terms of the…
We establish an empirical effective temperature calibration of main sequence, luminosity class V to III B-type stars for the Delta a photometric system which was originally developed to detect magnetic chemically peculiar objects of the…
We conducted a study on the thermal properties of stellar matter with the nuclear energy density functional BCPM. This functional is based on microscopic Brueckner-Hartree-Fock calculations and has demonstrated success in describing cold…
The star formation, mass assembly and chemical enrichment histories of galaxies, and their present distributions of dark matter, remain encoded in their stellar populations. Distinguishing the actual distribution functions of stellar age,…
We investigate the luminosity-temperature ($L$-$T$) relation of galaxy clusters as a probe for testing modified gravity (MG) theories, focusing on $f(R)$ gravity and symmetron models. Using an improved semi-analytic framework that…
Using the momentum-dependent MDI effective interaction for nucleons, we have studied the transition density and pressure at the boundary between the inner crust and liquid core of hot neutron stars. We find that their values are larger in…
We present a methodical study of the thermal and nuclear properties for the hot nuclear matter using relativistic-mean field theory. We examine the effects of temperature on the binding energy, pressure, thermal index, symmetry energy, and…
We derive the fundamental parameters (temperature and luminosity) of 107 619 Hipparcos stars and place these stars on a true Hertzsprung-Russell diagram. This is achieved by comparing BT-Settl model atmospheres to spectral energy…
We combine results from interferometry, asteroseismology and spectroscopic analyses to determine accurate fundamental parameters (mass, radius and effective temperature) of 10 bright solar-type stars covering the H-R diagram from spectral…
The temperature dependence of stellar electron-capture (EC) rates is investigated, with a focus on nuclei around $N=50$, just above $Z=28$, which play an important role during the collapse phase of core-collapse supernovae (CCSN). Two new…