Detailed abundances of a large sample of giant stars in M 54 and in the Sagittarius nucleus E. Carretta, A. Bragaglia, R. G. Gratton, S. Lucatello, M. Bellazzini, G. Catanzaro, F. Leone, Y. Momany, G. Piotto and V. D'Orazi A&A, 520 (2010) A95 Published online: 08 October 2010 DOI: 10.1051/0004-6361/201014924