TAP Colloquium

Monday, Jan 28, 2013
4:00 pm
Location: Steward Observatory
Room: N210

Dr. Konstantin Batygin
Caltech

"The Origin of Orbital Obliquity in Hot Exoplanetary Systems"

Abstract:
The presence of gaseous giant planets whose orbits lie in extreme proximity to their host stars ('hot Jupiters"), can largely be accounted for by planetary migration, associated with viscous evolution of proto-planetary nebulae. Recently, observations of the Rossiter-McLaughlin effect during planetary transits have revealed that a considerable fraction of detected hot Jupiters reside on orbits that are misaligned with respect to the spin-axes of their host stars. This observational fact has cast significant doubts on the importance of disk-driven migration as a mechanism for production of hot Jupiters, thereby reestablishing the origins of close-in planetary orbits as an open question.

In this talk, I will show that misaligned orbits can be a natural consequence of disk migration. The argument rests on an enhanced abundance of binary stellar companions in star formation environments, whose orbital plane is uncorrelated with the spin axes of the individual stars. I will construct a conservative model for the dynamical evolution of a self-gravitating proto-planetary disk under perturbations from a distant stellar companion and demonstrate that the gravitational torques of the binary companion act to misalign the orbital plane of the disk relative to the spin pole of the star.

Host:
Tami Rogers, tami@lpl.arizona.edu

TAP Colloquia