2015A&A...582A..13G

The trans-Neptunian region of the solar system is populated by a wide variety of icy bodies showing great diversity in orbital behavior, size, surface color, and composition. We present new ultraviolet, visible and near-infrared spectroscopic measurements for the trans-Neptunian object (278361) 2007 JJ₄₃, which is a dwarf planet candidate. The observations were performed with the instrument X-Shooter for the 8.2m ESO Very Large Telescope mounted on the UT2 at the Paranal Observatory in Chile. This spectrograph covers the entire 300-2480nm spectral range at once with a high resolving power. We analyzed the surface composition by modeling the spectra in the complete wavelength range and tried to detect icy compounds. We searched for spectral heterogeneity by comparing spectra obtained at different regions. The spectrum obtained is quite flat and 2007 JJ₄₃ can be classified as a blue-red object. No absorption bands of icy elements were detected in the spectra. However, our models indicate that crystalline water ice is probably not present on the surface in more than a concentration of 6.5%. Observations covering about one-third of the entire surface do not present any differences, suggesting that the surface is apparently homogeneous.