Rotational properties of Centaurs and Trans-neptunian objects: results from the ESO large program

In order to increase the sample of known TNO rotational rates, in the framework of the ESO Large Program 178.C0036 (P.I.: M. A. Barucci), we carried out at ESONTT (La Silla, Chile) photometric observations of 2 Centaurs (12929 1999 TZ1 and 95626 2002 GZ32) and 10 TNOs (42355 Ty phon, 47932 2000 GN171, 65489 Ceto, 90568 2004 GV9, 120132 2003 FY128, 144897 2004 UX10, 145451 2005 RM43, 145453 2005 RR43, 2003 UZ117 and 2003 UZ413). Results: Applying the method based on the Fourier analysis of the lightcurves, developed by Harris et al., rotational synodic periods were computed. We determined the spin rate for several objects and we confirmed previously published periods of two of them. For the objects for which we computed the rotational period, we estimated the axis ratio a/b, and hence their density. Our results seem to confirm the density/dimension trend found by Sheppard et al., with larger (brighter) objects having higher densities. The obtained complete results will be presented and discussed.