VLT observations of turnoff stars in the globular cluster NGC 6397 F. Thévenin, C. Charbonnel, J. A. de Freitas Pacheco, T. P. Idiart, G. Jasniewicz, P. de Laverny and B. Plez A&A, 373 3 (2001) 905-915 Published online: 15 July 2001 DOI: 10.1051/0004-6361:20010672