Yoram Lithwick, Northwestern University

 Secular Chaos: Formation of Hot Jupiters and the Organization of Planetary Systems

In a planetary system with well-spaced planets, there is a nonlinear instability that can lead to chaotic behaviour.  One of the planets may gradually become unstable,  in which case its orbit can become highly eccentric.  If an unstable planet comes close to the star, its orbit will be circularized by tides.  This can explain the numerous Jupiter-mass planets that have been discovered to orbit very close to the central star ("hot Jupiters").  After an unstable planet escapes the influence of the other planets, the remaining planetary system becomes  increasingly  stable.  This may explain the stable architecture of observed systems.

Host:  Dong Lai