Title: Produce Highly-Eccentric Planets by the Dispersal of Eccentric Disks

Abstract: Observations suggest that exoplanets often have non-negligible orbital eccentricities. These eccentricities are usually interpreted as results of planet-planet scatterings or secular perturbations due to distant companions. This talk will propose a different mechanism for planets to become eccentric (e.g., e~0.4 and higher). This mechanism requires only one planet and a slightly eccentric disk outside the planetary orbit. The disk may acquire its initial eccentricity from the disk eccentric mode instability. Then, as the disk slowly depletes, it naturally "sends" its eccentricity to the planet when the disk and the planet precess at the same rate. The first half of this talk will explain the eccentric mode instability using both linear theory and hydrodynamics simulations. The second half will adopt a simple long-term secular dynamics model to calculate the planet eccentricities that the eccentric disks can induce and discuss why and when this mechanism is efficient.

Host: Eric Ford

Seminar held in 538 Davey or please email CEHW-SEMINAR-QUESTIONS@lists.psu.edu to attend virtually.