Search for surface variations on TNO 47171 and Centaur 32532 F. Merlin, M. A Barucci, E. Dotto, C. de Bergh and G. Lo Curto A&A, 444 3 (2005) 977-982 Published online: 05 December 2005 DOI: 10.1051/0004-6361:20053642