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K.T. Hole, D.D. Sasselov, P.T. Kondratko, C.O. Heinke, S. Schnee, A.Z. Bonanos, G. Ball (Harvard-Smithsonian CfA)
Recent studies have established a correlation between stars with extrasolar planets and enhanced observed metallicity as compared with the general population. One explanation for the enhancement, suggested by the close orbits of the planets so far discovered, is the pollution of convection zones of host stars by the infall of planetary material. The process of planet destruction in the outer layers of the star makes a significant impact on the observed stellar metallicity resulting from the consumption.
We present results of modeling the destruction of both terrestrial and gaseous planets by shock heating and ablation in stars from 0.8 to 1.6 M\odot, as well as the predicted metallicity enhancements. Our results show that higher mass stars are more efficiently polluted than those with lower masses, primarily due to slower orbital decay, higher temperatures and the smaller mass of the surface mixing layer. We conclude that the consumption model does not well reproduce the observed distribution of metallicity enhancement of the extrasolar planet host stars.
Support provided by NASA contract NAS8-39073.
The author(s) of this abstract have provided an email address for comments about the abstract: khole@cfa.harvard.edu