Thermal properties of asteroid 21 Lutetia from Spitzer Space Telescope observations P. L. Lamy, O. Groussin, S. Fornasier, L. Jorda, M. Kaasalainen and M. A. Barucci A&A, 516 (2010) A74 Published online: 09 July 2010 DOI: 10.1051/0004-6361/201014361