Day 3 of the conference saw several talks on spin-orbit misalignments and mean-motion resonances in exoplanetary systems.
Among the talks on spin-orbit misalignment, Josh Winn of MIT gave an excellent review of observational and theoretical developments in the field. He argued that any model to explain the misalignments must account for (1) the fact that 75% of hot Jupiters show significant misalignment, (2) misaligned systems are found preferentially around stars hotter than 6100 K, and (3) misalignments out to 10 days orbital period. Hefty requirements that no theory for misalignment has convincingly satisfied yet.
In the resonances session, Konstantin Batygin of Caltech gave a sparkling talk on his recent work looking at the establishment of resonances in planetary systems. He showed how effective resonance capture requires fairly small orbital eccentricities, less than about 0.02. His results could help explain why so many multi-planet systems are very near but not quite in resonance.
