An internet server for update pre-main sequence tracks of low- and intermediate-mass stars

TL;DR

This paper introduces new pre-main sequence stellar evolution models for low- and intermediate-mass stars across various metallicities, along with an online tool for parameter determination and isochrone generation.

Contribution

It provides updated PMS tracks with improved physics and a new online server for stellar parameter analysis and isochrone computation.

Findings

Models validated against other grids for low-mass stars.

New physics updates improve model accuracy.

Online server enhances accessibility for observational data analysis.

Abstract

We present new grids of pre-main sequence (PMS) tracks for stars in the mass range 0.1 to 7.0 Msun. The computations were performed for four different metallicities (Z=0.01, 0.02, 0.03 and 0.04). A fifth table has been computed for the solar composition (Z=0.02), including a moderate overshooting. We describe the update in the physics of the Grenoble stellar evolution code which concerns mostly changes in the equation of state (EOS) adopting the formalism proposed by Pols et al. (1995) and in the treatment of the boundary condition. Comparisons of our models with other grids demonstrate the validity of this EOS in the domain of very low-mass stars. Finally, we present a new server dedicated to PMS stellar evolution which allows the determination of stellar parameters from observational data, the calculation of isochrones, the retrieval of evolutionary files and the possibility to generate graphic outputs. WWW site : http://www-laog.obs.ujf-grenoble.fr/activites/starevol/evol.html