A&A 408, 1037-1045 (2003)
Late main-sequence evolution of lithium and berylliumL. Piau1, S. Randich2 and F. Palla2
1 Institut d'Astronomie et d'Astrophysique, ULB, CP226, 1050 Brussels, Belgium
2 INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
(Received 26 December 2002 / Accepted 4 June 2003 )
We examine the effects of the tachocline diffusion process on the surface abundances of light elements in solar-like stars ( ). Acting during main sequence evolution, the tachocline diffusion can account for the gradual decrease in lithium surface abundance while preserving beryllium, in agreement with the most recent observational data for open cluster stars older than the Hyades (~600 Myr). We show that helioseismology and observations of surface rotation demand a nearly solid-body rotation of solar analogs after 1 Gyr. By then, these stars have become slow rotators and lost most of their initial angular momentum. We argue that mixing due to angular momentum loss does not appear to be a viable mechanism to account for the observed abundances.
Key words: stars: evolution -- stars: rotation -- stars: interiors -- stars: abundances
© ESO 2003