Adrian Barker (CIERA/Northwestern)

Internal wave breaking and the fate of planets around solar-type stars

Internal gravity waves are excited at the interface between the convection and radiation zones of a solar-type star, by the tidal forcing of a short-period planet. I will describe the results of a detailed study into the fate of these waves as they approach the centre of a star, and the consequences for the tidal evolution of the planetary orbit. If the waves have large enough amplitudes to break, their resulting absorption can threaten the survival of sufficiently massive planets that excite them. The absence of wave breaking near the centre of a host star could provide an explanation for the survival, against tidal decay, of all short-period extrasolar planets observed around FGK stars. In addition, it provides predictions that will be tested by ongoing and future observations of transiting planets, such as WASP and Kepler.