A Pluto-Charon Sonata: Dynamical Limits on the Masses of the Small Satellites
Abstract
During 2005-2012, images from Hubble Space Telescope (HST) revealed four moons orbiting Pluto-Charon. Although their orbits and geometric shapes are well-known, the 2σ uncertainties in the masses of the two largest satellites—Nix and Hydra—are comparable to their HST masses. Remarkably, gravitational n-body computer calculations of the long-term system stability on 0.1-1 Gyr timescales place much tighter constraints on the masses of Nix and Hydra, with upper limits ∼10% larger than the HST mass. Constraints on the mass density using size measurements from New Horizons suggest Nix and Hydra formed in icier material than Pluto and Charon.
- Publication:
-
The Astronomical Journal
- Pub Date:
- August 2019
- DOI:
- 10.3847/1538-3881/ab2890
- arXiv:
- arXiv:1903.04520
- Bibcode:
- 2019AJ....158...69K
- Keywords:
-
- planets and satellites: dynamical evolution and stability;
- planets and satellites: individual: Pluto;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 20 pages of text, 3 tables, 9 figures, submitted to Astronomical Journal