Rest assured your posts are avidly followed and much appreciated by the ‘lay’ public. Can’t get enough of this noble pursuit.

When the planet-metallicity connection first became evident, there was a debate as to whether the connection might be the result of parent stars consuming their planetary progeny.

If this hypothesis is correct, then the planet-metallicity connection should be strongest among stars that have shallow convective envelopes. A planet that is consumed by a star will have its metals mixed through only the outer convective layer. Stars that are somewhat more massive than the Sun have very shallow convective envelopes, and so they should show this effect most clearly.

In 1997, Fred Adams and I wrote a paper, “Possible Stellar Metallicity Enhancements from the accretion of Planets” (see http://arxiv.org/abs/astro-ph/9710110) in which we did a statistical analysis of the metallicities of F-type main-sequence stars in the solar neighborhood. We found a marginally significant trend in the direction that one would expect if planets were frequently being accreted during the star-formation process. Over the past several years, however, it has become increasingly clear that most of the planet-metallicity correlation is due to high metallicity of the parent star-forming cloud. Pollution likely occurs, but it likely does not account for the bulk of the planet-metallicity correlation.

My prediction is that the planet-metallicity correlation will be substantially weaker if one considers Neptune-like ice-giant planets in addition to the Jovian-mass planets that are currently known.

Will this not skew the sample.