Fundamental Parameters of Nearby Stars from the Comparison with Evolutionary Calculations: Masses, Radii and Effective temperatures

TL;DR

This study uses Hipparcos data and stellar evolutionary models to accurately estimate fundamental parameters like masses, radii, and temperatures for nearby stars, achieving uncertainties of around 6-8%.

Contribution

It demonstrates the reliability of evolutionary models combined with Hipparcos data to determine stellar parameters for a large sample of nearby stars.

Findings

Masses estimated within ~8%.

Radii estimated within ~6%.

Effective temperatures estimated within ~2%.

Abstract

The Hipparcos mission has made it possible to constrain the positions of nearby field stars in the colour-magnitude diagram with very high accuracy. These positions can be compared with the predictions of stellar evolutionary calculations to provide information on the basic parameters of the stars: masses, radii, effective temperatures, ages, and chemical composition. The degeneracy between mass, age, and metallicity is not so large as to prevent a reliable estimate of masses, radii and effective temperatures, at least for stars of solar metallicity. The evolutionary models of Bertelli et al. (1994) predict those parameters finely, and furthermore, the applied transformation from the theoretical (log g-Teff) to the observational (Mv-B-V) plane is precise enough to derive radii with an uncertainty of ~ 6%, masses within ~ 8%, and Teffs within ~ 2% for a certain range of the stellar parameters. This is demonstrated by means of comparison with the measurements in eclipsing binaries and the InfraRed Flux Method. The application of the interpolation procedure in the theoretical isochrones to the stars within 100 pc from the Sun observed with Hipparcos provides estimates for 17,219 stars