Equilibrium Shapes of Large Trans-Neptunian Objects

Nicolas Rambaux (1) , Daniel Baguet (2) , Fréderic Chambat (3) , Julie Castillo-Rogez (4)

1 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
2 UTINAM - Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213)
3 LGL-TPE - Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement
4 JPL - Jet Propulsion Laboratory

The large transneptunian objects (TNO) with radii larger than 400 km are thought to be in hydrostatic equilibrium. Their shapes can bring clues on their internal structures that would reveal information on their formation and evolution. In this paper we explore the equilibrium figures of five TNOs and we show that the difference between the equilibrium figures of homogeneous and heterogeneous interior models can reach several kilometers for fast rotating and low density bodies. Such a difference could be measurable by ground-based techniques. This demonstrates the importance of developing the shape up to second and third order when modeling the shapes of large and rapid rotators.

Domaines: Astrophysique [astro-ph]

Nicolas Rambaux, Daniel Baguet, Fréderic Chambat, Julie Castillo-Rogez. Equilibrium Shapes of Large Trans-Neptunian Objects. The Astrophysical journal letters, 2017, 850 (1), pp.L9. ⟨10.3847/2041-8213/aa95bd⟩. ⟨hal-01662024⟩