When
3:30 p.m., Feb. 9, 2010
Where
Kuiper Space Sciences Building 308
Dr. Gordon Ogilvie from DAMTP at the University of Cambridge is the scheduled speaker.
Tidal interactions between a planet and its host star are important when the orbital separation is sufficiently small, and many such systems are being discovered by the transit method. Tidal dissipation in the planet generally leads to orbital circularization accompanied by heating of the planet, while dissipation in the star typically leads to the inward migration and eventual destruction of the planet. The spin-orbit alignment, measurable by the Rossiter-McLaughlin effect, is also modified. While the celestial mechanics can readily be studied using parametrized models, the fluid dynamics of tidal interactions is much richer than can be described using a constant tidal quality factor or lag time. I will discuss some of the mechanisms for tidal dissipation involving the excitation of low-frequency waves in rotating and/or stratified fluids and their dissipation through linear or nonlinear processes. While numerous uncertainties remain, the observational evidence from short-period extrasolar planets and from the satellites of giant planets in the solar system provide valuable constraints that will allow theories to be tested and refined.
Tidal interactions between a planet and its host star are important when the orbital separation is sufficiently small, and many such systems are being discovered by the transit method. Tidal dissipation in the planet generally leads to orbital circularization accompanied by heating of the planet, while dissipation in the star typically leads to the inward migration and eventual destruction of the planet. The spin-orbit alignment, measurable by the Rossiter-McLaughlin effect, is also modified. While the celestial mechanics can readily be studied using parametrized models, the fluid dynamics of tidal interactions is much richer than can be described using a constant tidal quality factor or lag time. I will discuss some of the mechanisms for tidal dissipation involving the excitation of low-frequency waves in rotating and/or stratified fluids and their dissipation through linear or nonlinear processes. While numerous uncertainties remain, the observational evidence from short-period extrasolar planets and from the satellites of giant planets in the solar system provide valuable constraints that will allow theories to be tested and refined.