In a day of talks—I had to leave early a talk by Ruth Angus (Oxford) on stellar ages from Kepler to see a talk in Computer Science by Alekh Agarwal (Microsoft) on distributed and clever machine-learning algorithms and engineering—Bekki Dawson (Berkeley) showed us results on the statistics of exoplanet populations and tests of planetary migration scenarios. She showed that the continuity of tidal circularization models (conservative exoplanet flow, in some sense) makes a prediction for the distribution of planets in the period–eccentricity plane, and that the prediction is falsified strongly by Kepler. There is not yet any good model for the formation and migration of exoplanets that explains the main features of the data, but there are many possible effects, and it is possible that all of them are acting at some level. Her talk suggested scores of other projects that could and should be done. On a side note, she showed convincingly that you can measure eccentricities just with Kepler data alone, and that there are strong asymmetries that make it much more likely that you will see a faster-than-circular transit than a slower-than-circular transit when the transiting-planet orbit is eccentric. She also showed some transit timing work by our own Foreman-Mackey.
Perhaps it is useful to note to your readers that she showed Socrates et al. made the prediction.
ReplyDeletehttp://arxiv.org/abs/1110.1644