School of Physics and Astronomy

Astronomy Unit Seminar - Hydrodynamics of planetary envelopes

event image

25 January 2019

Time: 2:30 - 3:30pm
Speaker: William Bethune
Venue: GO Jones 610

Most of the identified exoplanets are expected to possess an atmosphere. Their diversity in mass and radius suggests that the gaseous envelope could sometimes reach several percent of the solid core mass. The extended gaseous envelopes observed now likely formed long before the dispersal of the parent disk, during the "embedded phase" of the core. The structure of such envelopes is often studied via one-dimensional (1D) models under the assumptions of spherical symmetry and quasi-staticity, allowing a sophisticated treatment of radiative and chemical effects. A prediction of 1D models is the rapid transition to gas giants for sufficiently massive cores. According to this criterion, a number of observed planets should have turned into gas giants. To better understand the origin of this disagreement, I will take the opposite position and examine the multi-dimensional and dynamical properties of embedded planetary envelopes under over-simplifying assumptions about their thermodynamics.