Astron. Astrophys. 346, 798-804 (1999)

Uncertainties in the Th cosmochronometry

S. Goriely  ^{*  1} and B. Clerbaux <sup>2

1</sup> Institut d'Astronomie et d'Astrophysique, C.P. 226, Université Libre de Bruxelles, B-1050 Brussels, Belgium
² Institut Inter-Universitaire des Hautes Energies, C.P. 230, Université Libre de Bruxelles, B-1050 Brussels, Belgium

Received 16 March 1999 / Accepted 20 April 1999

Abstract

Recent observations of r-nuclei, and in particular of Th, in ultra-metal poor stars revived the old idea that the Th cosmochronometry could provide an age estimate of the oldest stars in the Galaxy, and therefore a lower limit to the age of the Galaxy. Unfortunately, some nuclear, astrophysics and observational uncertainties still affect the theoretical r-process models required to predict the original production of Th. The impact of these uncertainties on the prediction of the age of the Galaxy is analyzed and discussed.

Key words: nuclear reactions, nucleosynthesis, abundances stars: abundances stars: individual: CS 22892-052

* S. Goriely is F.N.R.S. Research Associate.

Send offprint requests to: S. Goriely (sgoriely@astro.ulb.ac.be)

SIMBAD Objects

Contents

• 1. Introduction
• 2. Th cosmochronometry and the r-process
• 3. Uncertainties in the predicted Th abundance
  • 3.1. Sensitivity to astrophysics conditions
  • 3.2. Sensitivity to nuclear physics input
  • 3.3. Uncertainties in the solar r-abundance
• 4. The age of the stars
• 5. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: June 17, 1999
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