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 , where aH is the semimajor axis of the outermost moon Hydra. Small moons with radii ≲ 2 km and a ≲ 1.1 aH are ejected on timescales ranging from several years to more than 100 Myr. Orbits with a ≳ 1.1 aH 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.