Observatoire de Paris Institut national de recherche scientifique français Univerité Pierre et Marie Curie Université Paris Diderot - Paris 7

The Pluto System story told by resonances

mardi 9 mars 2021, par Thamiris Desantana (LESIA)

Lundi 15 mars 2021 à 16h00 , Lieu : En visioconférence

The Pluto-Charon system is very interesting due its complex dynamics. Its four small satellites Styx, Nix, Kerberos and Hydra were discovered close to, but not in, the 1:3, 1:4, 1:5, and 1:6 mean motion resonances with Charon, respectively (Cheng et al. 2014). Later, Styx, Nix, and Hydra were found to be in a three body resonance, a special configuration not so common among satellites and that provides clues to the origin of the system (Showalter and Hamilton 2015).

Abstract : In this work, we propose and seek evidence for a path to explain the satellites’ current positions. Our idea is to start with an early Charon migrating under tidal forces from Pluto, and the initial resonant capture of one or more of the small satellites into two-body resonance with Charon. Perhaps the most likely situation is that Styx was first captured into the 3:1 mean motion resonance. Subsequently, Styx would move outward while simultaneously having its eccentricity raised by the resonance. We hypothesize that additional captures of Hydra and Nix into mean motion resonances can, when activated together, turn on the three-body resonance. If the three body resonance takes control, Styx could, in principle, be adiabatially removed from its resonance with Charon and its eccentricity driven back toward zero.