A Pluto-Charon Sonata: The Dynamical Architecture of the Circumbinary Satellite System

Abstract

Using a large suite of n-body simulations, we explore the discovery space for new satellites in the Pluto-Charon system. For the adopted masses and orbits of the known satellites, there are few stable prograde or polar orbits with semimajor axes $a\lesssim 1.1a_H$, where $a_H$ is the semimajor axis of the outermost moon Hydra. Small moons with radii $r\lesssim$ 2 km and $a\lesssim 1.1a_H$ are ejected on time scales ranging from several yr to more than 10 Myr. Orbits with $a\gtrsim 1.1a_H$ are stable on time scales exceeding 100 Myr. Near-IR and mid-IR imaging with JWST and ground-based occultation campaigns with 2-3-m class telescopes can detect 1-2 km satellites outside the orbit of Hydra. Searches for these moons enable new constraints on the masses of the known satellites and on theories for circumbinary satellite formation.

34 pages of text, 2 tables, 12 figures, submitted to AAS journals, comments welcome. Animations associated with the paper are available at https://www.cfa.harvard.edu/~kenyon/Media/PCSonata.html