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

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≲ 1.1 {a}_H, where a _H is the semimajor axis of the outermost moon Hydra. Small moons with radii r ≲ 2 km and a ≲ 1.1 a _H are ejected on timescales ranging from several years to more than 100 Myr. Orbits with a ≳ 1.1 a _H are stable on timescales exceeding 150-300 Myr. Near-infrared (IR) and mid-IR imaging with several instruments on James Webb Space Telescope 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.