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| Paper: |
On the Roche Lobe Overflow of Giant Planets with Ultra-Short Periods due to Tidal Dissipation |
| Volume: |
294, Scientific Frontiers in Research on Extrasolar Planets |
| Page: |
209 |
| Authors: |
Gu, P.-G.; Bodenheimer, P. H.; Lin, D. N. C. |
| Abstract: |
We investigate the possibility of gross inflation of short-period Jupiter-mass planets, as a result of their internal tidal dissipation associated with the synchronization and circularization of their orbits. In the low-eccentricity limit, the synchronization of the planets' spin with their mean motion is established before their orbits are circularized. for young Jupiter-mass planets with a period less than 3 days, an initial radius about 2 Jupiter radii and an orbital eccentricity greater than 0.2, the energy dissipated during the circularization of their orbit is sufficiently intense and protracted to inflate their size up to that comparable with their Roche radii. We show that the planets with modest eccentricity (less than about 0.3) and semi-major axis around 0.02-0.04 AU lose mass via Roche-lobe overflow through their inner Lagrangian (L1) point. Due to the conservation of total angular momentum, these mass-losing planets migrate outwards, such that their semi-major axis and Roche radius increase while their mass, eccentricity, and tidal dissipation rate decrease until their mass loss is quenched. We estimate the mass loss rate, the asymptotic planetary masses and semi-major axis for various planetary initial orbital parameters. We suggest that these two types of self-regulated mass loss and migration processes may be responsible for the apparent lack of giant planets with ultra-short periods less than 3 days. It may account for the relatively low mass of the planets with short-period of about 3-7 days and the high metallicity of their host stars. |
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