Habitable planets around the star Gliese 581? F. Selsis, J. F. Kasting, B. Levrard, J. Paillet, I. Ribas and X. Delfosse A&A, 476 3 (2007) 1373-1387 Published online: 06 November 2007 DOI: 10.1051/0004-6361:20078091