Ring Dynamics Around Non-Axisymmetric Bodies B
Ring dynamics around non-axisymmetric bodies B. Sicardy∗;1, R. Leiva2, S. Renner3, F. Roques1, M. El Moutamid4;5, P. Santos-Sanz6, J. Desmars1 1 LESIA, Observatoire de Paris, Universit´e PSL, CNRS, UPMC, Sorbonne Universit´e, Univ. Paris Diderot, Sorbonne Paris 2 Cit´e, 5 place Jules Janssen, 92195 Meudon, France Southwest Research Institute, Dept. of Space Studies,1050 Walnut 3 Street, Suite 300, Boulder, CO 80302, USA. IMCCE, Observatoire de Paris, CNRS UMR 8028, Universite de Lille, 4 Observatoire de Lille, 1, impasse de l'Observatoire, F-59000 Lille, France. Center for Astrophysics and Planetary Science, 5 6 Cornell University, Ithaca, NY 14853, USA. Carl Sagan Institute, Cornell University, Ithaca, NY 14853, USA. Instituto de Astrof´ısica de Andaluc´ıa (CSIC), Glorieta de la Astronom´ıa S/N, 18008-Granada, Spain. Dense and narrow rings have been discovered recently around the small Centaur object 1 2 3 Chariklo and the dwarf planet Haumea , while being suspected around the Centaur Chiron . They are the first rings observed in the Solar System elsewhere than around giant planets. Contrarily to the latters, gravitational fields of small bodies may exhibit large non-axisymmetric terms that create strong resonances between the spin of the object and the mean motion of rings particles. Here we show that modest topographic features or elongations of Chariklo and Haumea explain why their rings are relatively far away from the central body, when scaled to those of the giant planets. Lindblad-type resonances actually clear on decadal time-scales an initial collisional disk that straddles the corotation resonance (where the particles mean motion matches the spin rate of the body).
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