The 16 Cygni system: A laboratory for studying the influence of a planetary system on its host star
Morgan Deal

The accretion of heavy planetary matter onto main-sequence stars leads to fingering instabilities induced by the inverse mu-gradient. This leads to an extra convection zone which rapidly mixes the accreted matter inside the star. A first consequence of this mixing is that no signature of the accreted heavy elements remains at the surface. A second consequence is that, due to the extra mixing, an important quantity of lithium may be rapidly destroyed. Such an effect can explain the abundance differences observed in the two main stars of the 16 Cygni system.