Talk abstract details

The effect of stellar magnetic braking on the evolution of close-in extrasolar planets orbiting main-sequence stars
Adrian Barker, Gordon Ogilvie

Abstract

Tidal friction is thought to be important in determining the long term spin-orbit evolution of short period extrasolar planetary systems. Using a simple model of the orbit averaged effects of tidal friction (Mardling & Lin, 2002) based on the constant lag time model of Hut (1981), we analyse the effects of the inclusion of stellar magnetic braking on the secular evolution of such systems. A phase-plane analysis of a simplified system of equations including only the stellar tide together with a model of the magnetic braking torque first proposed by Verbunt & Zwaan (1981) for main-sequence stars, is presented. We then show the results of numerical integrations of the full tidal evolution equations for a set of systems containing close-in extrasolar planets around main-sequence dwarfs including the stellar magnetic braking torque. The evolution of eccentricity and inclination is calculated for these systems, as is the tidal heating of the planet. The inclusion of stellar magnetic braking is found to be extremely important in determining the secular evolution of such systems, and its neglect results in a very different orbital history.