Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307 M. Tuomi, G. Anglada-Escudé, E. Gerlach, H. R. A. Jones, A. Reiners, E. J. Rivera, S. S. Vogt and R. P. Butler A&A, 549 (2013) A48 Published online: 17 December 2012 DOI: 10.1051/0004-6361/201220268