Planet Consumption and Stellar Metallicity Enhancements

The evolution of a giant planet within the stellar envelope of amain-sequence star is investigated as a possible mechanism for enhancing thestellar metallicities of the parent stars of extrasolar planetary systems.Three-dimensional hydrodynamical simulations of a planet subject to impactingstellar matter indicate that the envelope of a Jupiter-like giant planet can becompletely stripped in the outer stellar convection zone of a solar-mass star.In contrast, Jupiter-like and less massive Saturn-like giant planets are ableto survive through the base of the convection zone of a 1.22 solar-mass star.Although strongly dependent on details of planetary interior models, partial ortotal dissolution of giant planets can result in significant enhancements inthe metallicity of host stars with masses between about 1.0 and 1.3 solarmasses. The implications of these results with regard to planetary orbitalmigration are briefly discussed.Comment: 11 pages, 2 figures, accepted for ApJ Letter