Astron. Astrophys. 364, 674-682 (2000)

Detailed analysis of a sample of Li-rich giants ^* **

B.V. Castilho ^1,2, J. Gregorio-Hetem ¹, F. Spite ³, B. Barbuy ¹ and M. Spite <sup>3

1</sup> Universidade de São Paulo, CP 3386, São Paulo, SP, 01060-970, Brazil
² Laboratório Nacional de Astrofísica, CP 21, Itajubá, MG, 37500-000, Brazil
³ Universidade de São Paulo, CP 3386, São Paulo, SP, 01060-970, Brazil
⁴ Observatoire de Paris-Meudon, DASGAL, URA 8633 CNRS, F-92195 Meudon Cedex, France

Received 24 July 2000 / Accepted 18 October 2000

Abstract

A detailed analysis has been carried out for a sample of 16 red giants showing a strong Li I 670.8 nm line. Ten of them were detected in a survey by Castilho et al. (1998), and the other 6 stars are Li-rich giants selected from the literature.

Element abundances in the sample Li-rich giants are similar to those in normal red giants, differing only by their high Li abundance and infrared excess. This suggests that Li-rich giants may correspond to a phase of stellar evolution of normal red giants, when Li is produced and transported to the atmosphere.

Key words: stars: late-type stars: evolution stars: atmospheres stars: abundances

* Observations collected at the European Southern Observatory - ESO, Chile, Laboratório Nacional de Astrofísica - LNA, Brazil and Observatoire de Haute Provence - OHP, France
** Table 7 is available only in electronic form at the CDS via anonymous ftp to ftp://cdsarc.u-strasbg.fr/pub/J/A+A/364/674 (130.79.128.5) or via http://cdsweb.u-strsbg.fr/cgi-bin/qcat?J/A+A/364/674

Send offprint requests to: B.V. Castilho

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and data reduction
• 3. Calculations
  • 3.1. Stellar parameters
    • 3.1.1. Temperature
    • 3.1.2. Gravity
  • 3.2. Curves of growth: metallicity and
• 4. Influence of atmospheric parameters on abundances
• 5. Results
  • 5.1. Lithium abundance
  • 5.2. Other elements
• 6. General discussion
• 7. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: January 29, 2001
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