Physics Colloquium - Are planetary systems flat?

Event Date: 

Tuesday, October 29, 2013 - 4:00pm

Event Location: 

  • Broida 1640

Event Contact: 


Scott Tremaine, Institute for Advanced Study, Princeton University


Laplace argued, correctly, that the small inclinations of planetary orbits implied that the solar system formed from a flat disk.  The observational and theoretical evidence on whether extrasolar planetary systems are flat, however, is still ambiguous. I will discuss constraints on flatness from the Kepler spacecraft and other sources; measurements of the Rossiter-McLaughlin effect in transiting planets, which show that many planetary systems have misaligned stellar spin and planetary orbital angular momenta; Lidov-Kozai oscillations; and competing migration mechanisms for the formation of giant planets at small orbital radii.