Using non-solar-scaled opacities to derive stellar parameters

Accuray of Stellar Opacities and the Solar Abundance Problem

The abundances of some of the most common elements in the Sun has been called into question by recent analysis based on new non-LTE hydrodynamic models. The new abundances of C, N, O, Ne etc. are 30-40% lower than the ’standard’ solar abundances, which were heretofore well established and supported by precise helioseismological observations. A number of recent studies have addressed the issue f...

RADIATIVE OPACITIES AND STEllAR PULSATIONS

A Large Stellar Evolution Database for Population Synthesis Studies. I. Scaled Solar Models and Isochrones

We present a large and updated stellar evolution database for low-, intermediateand high-mass stars in a wide metallicity range, suitable for studying Galactic and extragalactic simple and composite stellar populations using population synthesis techniques. The stellar mass range is between∼ 0.5M⊙ and 10M⊙ with a fine mass spacing. The metallicity [Fe/H] comprises 10 values ranging from −2.27 t...

Solar Models with Revised Abundances and Opacities

Using reconstructed opacities, we construct solar models with low heavyelement abundance. Rotational mixing and enhanced diffusion of helium and heavy elements are used to reconcile the recently observed abundances with helioseismology. The sound speed and density of models where the relative and absolute diffusion coefficients for helium and heavy elements have been increased agree with seismi...

Constraining fundamental stellar parameters using seismology

We apply the Levenberg-Marquardt minimization algorithm to seismic and classical observables of the αCen binary system in order to derive the fundamental parameters of αCenA+B, and to analyze the dependence of these parameters on the chosen observables, on their uncertainty, and on the physics used in stellar modelling. The seismological data are those by Bouchy & Carrier (2002) for αCen A, and...