The Na-O anticorrelation in horizontal branch stars - III. 47 Tucanae and M 5 R. G. Gratton, S. Lucatello, A. Sollima, E. Carretta, A. Bragaglia, Y. Momany, V. D’Orazi, S. Cassisi, A. Pietrinferni and M. Salaris A&A, 549 (2013) A41 Published online: 13 December 2012 DOI: 10.1051/0004-6361/201219976