Astron. Astrophys. 361, 1023-1035 (2000)

Evolutionary tracks and isochrones for -enhanced stars

B. Salasnich ¹, L. Girardi ^1,2, A. Weiss ² and C. Chiosi <sup>1

1</sup> Department of Astronomy, University of Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy
² Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Strasse 1, 85740 Garching bei München, Germany

Received 22 May 2000 / Accepted 14 July 2000

Abstract

We present four large sets of evolutionary tracks for stars with initial chemical compositions , , and and enhancement of elements with respect to the solar pattern. The major improvement with respect to previous similar calculations is that we use consistent opacities - i.e. computed with the same chemical composition as adopted in the stellar models - over the whole relevant range of temperatures. For the same initial chemical compositions and otherwise identical input physics we present also new evolutionary sequences with solar-scaled mixtures of abundances. Based on these stellar models we calculate the corresponding sets of isochrones both in the Johnson-Cousins UBVRIJHK and HST/WFPC2 photometric systems. Furthermore, we derive integrated magnitudes, colours and mass-to-light ratios for ideal single stellar populations with total mass equal to . Finally, the major changes in the tracks, isochrones, and integrated magnitudes and colours passing from solar-scaled to -enhanced mixtures are briefly outlined. Retrieval of the complete data set is possible via the www page http://pleiadi.pd.astro.it .

Key words: stars: evolution stars: interiors stars: Hertzsprung Russel (HR) and C-M diagrams

Send offprint requests to: L. Girardi (lgirardi@pd.astro.it)

This article contains no SIMBAD objects.

Contents

• 1. Introduction
• 2. Stellar tracks
  • 2.1. Input physics
    • 2.1.1. Initial chemical composition
    • 2.1.2. Opacities
    • 2.1.3. Neutrino losses
    • 2.1.4. Remaining physical input
  • 2.2. HR diagram
• 3. Isochrones
  • 3.1. Isochrones in the HR-diagram
  • 3.2. Theoretical Johnson and HST photometry
  • 3.3. Integrated magnitudes and mass-to-light ratios of single stellar populations
• 4. Concluding remarks
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: October 10, 2000
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