Related papers: Stellar models and Hyades: the Hipparcos test
Accurate determinations of masses and radii in binary stars, along with estimates of the effective temperatures, metallicities, and other properties, have long been used to test models of stellar evolution. As might be expected,…
Individual components of well-detached binary systems are assumed to be two single-like stars with a common origin, i.e. they share the same chemical composition and same age. Therefore, one expects to fit the observed parameters of both…
The discrepancy between a LONG distance scale derived from Hipparcos based distances to globular clusters via main sequence fitting to local subdwarfs, and a SHORT distance scale derived from the absolute magnitude of field RR Lyraes via…
We make use of the Next Generation model atmospheres by Allard et al. (1997) and Hauschildt, Allard & Baron (1999) to compute theoretical models for low and very low-mass stars for selected metallicities in the range Z= 0.0002 to 0.002. On…
We present Very Low Mass stellar models as computed including non-grey model atmospheres for selected assumptions about the star metallicities. The role of atmospheres is discussed and the models are compared with models based on the…
An effective model is used to study the equation of state of warm strange hadronic matter with nucleons, Lambda-hyperons, Xi-hyperons, sigmastar and phi. In the calculation, a newest weak Y-Y interaction deduced from the recent observation…
We have used the Simbad database and VizieR catalogue access tools to construct the observational color-absolute magnitude diagrams of nearby K-M dwarfs with precise Hipparcos parallaxes (\sigma_\pi/\pi < 0.05). Particular attention has…
In this contribution, I review the applications and potential limitations of the spectral energy distribution fitting tool that I have developed, with a strong emphasis on the limits to which this tool can be used to improve our…
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 status of the art for evolutionary models of low mass, population II stars is revisited, stressing the need for the models to be preliminarily tested with suitable observational data. The uncertainties still affecting the theory are…
We briefly review some constraints (Owing to the limited number of pages of present review, only a sub-sample of the topics discussed during the talk are briefly summarized. For the interested readers we are pleased to send them upon…
Context: Using the recent observational data of R\"oser et al. we present $N$-body simulations of the Hyades open cluster. Aims: We make an attempt to determine initial conditions of the Hyades cluster at the time of its formation in order…
We describe the results of a search for the remnants of the Sun's birth cluster among stars in the Hipparcos Catalogue. This search is based on the predicted phase space distribution of the Sun's siblings from simple simulations of the…
We examine contributions of second order physical processes to results of stellar evolution calculations amenable to direct observational testing. In the first paper in the series (Young et al. 2001) we established baseline results using…
This review summarises results of recent magnetic and chemical abundance surface mapping studies of early-type stars. We discuss main trends uncovered by observational investigations and consider reliability of spectropolarimetric inversion…
We are reaching relative maturity and standardization in one-dimensional single-star stellar evolution and pulsation modeling, and are making advances in binary and 2D and 3D models. However, many physical inputs are still uncertain or…
In order to better determine the physical properties of hot, massive stars as a function of metallicity, we obtained very high SNR optical spectra of 26 O and early B stars in the Magellanic Clouds. These allow accurate modeling even in…
We present 1D numerical simulations aimed at studying the hot-flasher scenario for the formation of He-rich subdwarf stars. Sequences were calculated for a wide range of metallicities and physical assumptions, such as the stellar mass at…
Interpreting the small-scale clustering of galaxies with halo models can elucidate the connection between galaxies and dark matter halos. Unfortunately, the modelling is typically not sufficiently accurate for ruling out models…
The correct interpretation of the large amount of complex data from next-generation (in particular, space-based) observational facilities requires a very strong theoretical underpinning. One can thus predict that in the near future the use…