High-contrast observations of (136108) Haumea
A crystalline water-ice multiple system⋆
C. Dumas1, B. Carry2,3, D. Hestroffer4 and F. Merlin2,5
European Southern Observatory. Alonso de Córdova 3107,
Vitacura, Casilla 19001,
Santiago de Chile,
2 LESIA, Observatoire de Paris, CNRS, 5 place Jules Janssen, 92195 Meudon Cedex, France
3 European Space Astronomy Centre, ESA, PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
4 IMCCE, Observatoire de Paris, CNRS. 77, Av. Denfert-Rochereau, 75014 Paris, France
5 Universit Paris 7 Denis Diderot, 4 rue Elsa Morante, 75013 Paris, France
Accepted: 6 January 2011
Context. 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. One can also see there are dynamical families and binary systems. One surprising feature detected in the spectra of some of the largest trans-Neptunians is the presence of crystalline water-ice. This is the case for the large TNO (136 108) Haumea (2003 EL61).
Aims. We seek to constrain the state of the water ice of Haumea and its satellites and to investigate possible energy sources that maintain the water ice in its crystalline form.
Methods. Spectro-imaging observations in the near infrared were performed with the integral field spectrograph SINFONI mounted on UT4 at the ESO Very Large Telescope. The spectra of both Haumea and its larger satellite Hi’iaka were analyzed. Relative astrometry of the components was also measured, providing a check of the orbital solutions and equinox seasons.
Results. We describe the physical characteristics of the crystalline water-ice present on the surface of Haumea and its largest satellite Hi’iaka and analyze possible sources of heating to maintain water in a crystalline state: tidal dissipation in the system components vs. radiogenic source. The surface of Hi’iaka appears to be covered by large grains of water ice, almost entirely in its crystalline form. Under some restricted conditions, both radiogenic heating and tidal forces between Haumea and Hi’iaka could provide the energy needed to maintain the ice in its crystalline state.
Key words: Kuiper belt objects: individual: (136108) Haumea / techniques: high angular resolution / techniques: imaging spectroscopy / methods: observational / infrared: planetary systems
Based on observations collected at the European Southern Observatory, Paranal, Chile - 60.A-9235.
© ESO, 2011