Princeton University Extrasolar Planet Discussion Group

Planets and satellites in mean-motion resonance offer a unique opportunity to probe complex effects of planet-disk interaction and tidal dissipation. I will first discuss how the orbit of Hyperion, a small satellite of Saturn, is inextricably coupled to its chaotic spin. By balancing the contributions from Titan and Hyperion's internal dissipation, tidal parameters can be measured and fine-tuning problems are avoided. I will then show that similar techniques can constrain the origin of the near-resonant Kepler exoplanets. Transit timing variations contain a wealth of information on the resonant dynamics that is usually ignored. I will show that the resonances are overly excited, and thus require a source of stochasticity in addition to disk-driven migration in order to match their current orbits.