The University of Western Ontario
DEPARTMENT OF PHYSICS AND ASTRONOMY
Special Undergraduate LevelTalk
Date: Tuesday, 17th April 2012
Time: 10:30 a.m.
Location: Physics & Astronomy Seminar Room 22
Dr. Nicolas Cowan
Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA)
Northwestern University, Illinois
“Tortured Climes: Infrared Observations of Hot Jupiters”
ABSTRACT
The discovery of gas giant planets in few-day orbits around their host stars posed serious challenges to theories of planet formation. In the last half-decade, our ability to probe the atmospheres of these hot Jupiters has likewise challenged our notions of climate. Many of these worlds have extremely eccentric orbits, leading to seasons that make Earth’s obliquity-driven seasons seem like a joke. For most Solar System planets, the dominant driver of heat transport is the equator-to-pole temperature gradient. On hot Jupiters, it is the huge day-night temperature contrast (from hundreds to thousands of degrees) that drives atmospheric circulation, potentially leading to transonic winds. Their atmospheres are slightly ionized, making magnetohydrodynamics relevant. Some of the shortest period gas giants have severely warped shapes due to tidal effects. In short, these planets are unlike anything climate scientists have thought much about.
I will present observational studies that can help constrain the mysterious workings of these planets. I will show how we can use time-resolved infrared photometry to learn about hot Jupiters.