SCYON Abstract

Received on October 4 2006

New Abundances for Old Stars – Atomic Diffusion at Work in NGC 6397

AuthorsAndreas Korn (1), Frank Grundahl (2), Olivier Richard (3), Paul Barklem (1), Lyudmila Mashonkina (4), Remo Collet (1), Nikolai Piskunov (1), and Bengt Gustafsson (1)
Affiliation
(1) Uppsala Astronomical Observatory, Sweden
(2) Århus University, Denmark
(3) University of Montpellier II, France
(4) Institute of Astronomy, Moscow, Russia
To appear inThe Messenger 125, 6 (2006)
Contactakorn@astro.uu.se
URLhttp://www.eso.org/messenger
Links

Abstract

A homogeneous spectroscopic analysis of unevolved and evolved stars in the metal-poor globular cluster NGC 6397 with FLAMES-UVES reveals systematic trends of stellar surface abundances that are likely caused by atomic diffusion. This finding helps to understand, among other issues, why the lithium abundances of old halo stars are significantly lower than the abundance found to be produced shortly after the Big Bang.