McGill.CA / Science / Department of Physics

Physical Society Colloquium

Special Physics Seminar

Tidal Evolution of Close-in Exo-Planets

Yangin Wu

CITA
University of Toronto

A recent major break-through in astronomy is the discovery of extra-solar planets. These are mostly Jupiter-mass gaseous planets closely orbiting their host stars. And at last count we know ~80 such planets. Their orbital characteristics differ from those in our solar system in many aspects, thereby revolutionizing our understanding of planet formation and evolution.

Many of these that are very close to their host stars have suffered tidal dissipation and have completely or partially circularized orbits. We use this ensemble to tightly constrain the rate of tidal dissipation, a process little understood in giant planets (and many other celestial bodies). I will also discuss two planets that appear to defy the above picture of tidal circularization. HD 83443b, the exoplanet with the smallest semi-major axis, has a significantly non-zero eccentricity; HD 80606b, the exoplanet with the closest periapstron approach, has an exotically high eccentricity of 0.93. I offer solutions for these oddities which have implications for the process of planet migration, a process which our solar system alone (?) do not seem to have gone through.

Wednesday, February 6th 2002, 11:00
Ernest Rutherford Physics Building, Boardroom - room 104