Jonathon Langton
University of California at Santa Cruz
Atmospheric Dynamics on Unevenly Irradiated Jovian Planets
Monday, May 12, 2008, 4:00 p.m.
Location: Thornton Hall 411
Refreshments at 3:45 p.m.
ABSTRACT
The increasingly rapid pace of the discovery of extrasolar planets
has brought to light a number of worlds with properties vastly different
from those in out own solar system. Dramatic examples of this variety
are provided by a class of planets with highly eccentric (e> 0.3) orbits,
with very close (a(1-e) < 0.05 A.U.) periastron passages. On these
planets, the subsolar irradance varies by a factor of 3 to 1000, typically
reaching ~10^6 W/m^2 at periastron.
I will present the results of two-dimensional hydrodynamic simulations of
the upper atmospheres of these planets. The flow geometry is complex,
turbulent, and primarily driven by the sudden influx of energy at periastron.
I will focus attention on 4 particularly interesting planets.
HD 80606 b (e= 0.9321) has the largest eccentricity of any planet yet
discovered. HAT-P-2 b (e=0.507) presents a particularly promising
observational target due to the large infrared flux variation we predict,
and due to the fact that it transits its parent star. HD 17156 b (e= 0.67)
also transits. Finally, HD 37605 b (e=0.737), while not particularly
suitable for observation, occupies an especially interesting dynamical
regime, with persistent circumpolar vortices shielding their interiors from
most of the periastron heating.