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The Swallowing of Planets by Giant Stars

Lionel Siess·Mario Livio
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Abstract

We present simulations of the accretion of a massive planet or brown dwarf by an AGB star. In our scenario, close planets will be engulfed by the star, spiral-in and be dissipated in the ``accretion region'' located at the bottom of the convective envelope of the star. The deposition of mass and chemical elements in this region will release a large amount of energy that will produce a significant expansion of the star. For high accretion rates, hot bottom burning is also activated. Finally, we present some observational signatures of the accretion of a planet/brown dwarf and we propose that this process may be responsible for the IR excess and high lithium abundance observed in 4-8% of single G and K giants.

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Lionel Siess, Mario Livio. 1998-08-14. The Swallowing of Planets by Giant Stars. https://arxiv.org/abs/astro-ph/9808153

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