Structure of the outer layers of cool standard stars S. Dehaes, E. Bauwens, L. Decin, K. Eriksson, G. Raskin, B. Butler, C. D. Dowell, B. Ali and J. A. D. L. Blommaert A&A, 533 (2011) A107 Published online: 12 September 2011 DOI: 10.1051/0004-6361/200912442