Planet consumption and stellar metallicity enhancements

The evolution of a giant planet within the stellar envelope of a main-seque nce star is investigated as a possible mechanism for enhancing the stellar metallicities of the parent stars of extrasolar planetary systems. Three-di mensional hydrodynamical simulations of a planet subject to impacting stell ar matter indicate that the envelope of a Jupiter-like giant planet can be completely stripped in the outer stellar convection zone of a 1 M. 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 M. star. Alth ough 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 in the range 1.0 M. less than or similar to M less than or similar to 1.3 M.. The implications of these r esults with regard to planetary orbital migration are briefly discussed.