2009A&A...508..451P

Trans-Neptunian objects (TNOs) represent a new frontier in the study of our Solar System. In particular, the investigation of their rotational properties can provide important hints about their internal structure and collisional evolution. We expand the limited sample of TNOs with known rotation rates, and improve the knowledge of the physical nature of these bodies. We carried out photometric observations of 5 TNOs (144897 2004 UX₁₀, 145451 2005 RM₄₃, 145453 2005 RR₄₃, 2003 UZ₁₁₇, and 2003 UZ₄₁₃) using the New Technology Telescope of the European Southern Observatory. We determined the spin rates of four targets, while only an estimation of the period was possible for 2003 UZ₁₁₇. From the computed rotational periods and the obtained light curve amplitudes of four TNOs, we derived the lower limit to their axis ratio a/b, and hence estimated their density. Combining our new results with literature data, we investigated the density statistics of the small bodies of the outer Solar System.