Thermal properties of asteroid 21 Lutetia from Spitzer Space Telescope observationsP. L. Lamy, O. Groussin, S. Fornasier, L. Jorda, M. Kaasalainen and M. A. BarucciA&A, 516 (2010) A74DOI: https://doi.org/10.1051/0004-6361/201014361