AAS 201st Meeting, January, 2003
Session 17. Stellar Evolution and Metal-Poor Stars
Poster, Monday, January 6, 2003, 9:20am-6:30pm, Exhibit Hall AB

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[17.06] The Impact of Pollution on Stellar Evolution Models

A. L. Dotter, B. C. Chaboyer (Dartmouth College)

It has been suggested the formation of planets around a star will lead to debris from the protoplanetary disk hitting the surface of the star. Such stellar 'pollution' will alter the heavy element content in the surface layers of the parent star. We present stellar evolution models that include stellar pollution. We find that polluted models of stars with known planets can have noticeably higher surface temperatures than an unpolluted model with similar mass and [Fe/H]. We discuss results pertaining to the planet-harboring star \tau Bootis.

Stellar pollution is considerably smaller in most stars (like our Sun) which do not have giant planets in close orbits. For these stars, stellar pollution has only a modest effect on the star's evolution. Stars in the Hyades open cluster all have the same age, and presumably the same initial heavy element content. As a result, Hyades stars show a tight relationship between color and absolute magnitude. Stellar pollution does not lead to a noticeable increase in the dispersion of stars in a color-magnitude diagram and we demonstrate that the polluted models are consistent with the Hyades color-magnitude diagram. Finally, we present our findings on a mass-[Fe/H] relation in the Hyades.

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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.