Planet Consumption and Stellar Metallicity Enhancements

Abstract

The evolution of a giant planet within the stellar envelope of a main-sequence star is investigated as a possible mechanism for enhancing the stellar metallicities of the parent stars of extrasolar planetary systems. Three-dimensional hydrodynamical simulations of a planet subject to impacting stellar matter indicate that the envelope of a Jupiter-like giant planet can be completely stripped in the outer stellar convection zone of a solar-mass star. In contrast, Jupiter-like and less massive Saturn-like giant planets are able to 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 or total dissolution of giant planets can result in significant enhancements in the metallicity of host stars with masses between about 1.0 and 1.3 solar masses. The implications of these results with regard to planetary orbital migration are briefly discussed.Comment: 11 pages, 2 figures, accepted for ApJ Letter