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

摘要

The Hipparcos mission has made it possible to constrain the positions ofnearby field stars in the colour-magnitude diagram with very high accuracy.These positions can be compared with the predictions of stellar evolutionarycalculations 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 toprevent a reliable estimate of masses, radii and effective temperatures, atleast for stars of solar metallicity. The evolutionary models of Bertelli etal. (1994) predict those parameters finely, and furthermore, the appliedtransformation from the theoretical (log g-Teff) to the observational (Mv-B-V)plane is precise enough to derive radii with an uncertainty of ~ 6%, masseswithin ~ 8%, and Teffs within ~ 2% for a certain range of the stellarparameters. This is demonstrated by means of comparison with the measurementsin eclipsing binaries and the InfraRed Flux Method. The application of the interpolation procedure in the theoretical isochronesto the stars within 100 pc from the Sun observed with Hipparcos providesestimates for 17,219 stars