exoplanet dynamics, sucking

In group meeting, Dun Wang talked about astrometric calibration of the GALEX Satellite, and Kat Deck (Caltech) talked about the dynamical evolution of exoplanetary systems. She pointed out that we naively expect lots of planets close in period to be locked in resonances, but in fact such resonances are rare, empirically in the Kepler sample. She has explanations for this involving the evolving proto-planetary disk.

After lunch, Deck gave the astro seminar, on planetary system stability and the Kepler planets. She discussed chaos, stability, and heuristic stability criteria. One interesting thing is that there really is no non-heuristic stability criterion: We think of a planetary system as "stable" if there are no catastrophic, order-unity changes to any of the orbital osculating elements. That's not really an equation! And at the talk there was some discussion of the point (counter-intuitive and important) that a system can be stable (by our astronomer definition) for far, far longer than the Lyapunov time. Awesome and important.

At the end of the day, Foreman-Mackey and I made the (astonishing) decision to abort and fail on our NASA proposal: We just ran out of time. I am disappointed; we have an eminently fundable pitch. That said, we just didn't start early enough to make that pitch at the level we wanted. Not sure how to feel about it, but I sure need to catch up on sleep!

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