3D Hydrodynamical Simulations of a Brown Dwarf Accretion by a Main-Sequence Star and its Impact on the Surface Li Abundance

Li-depleted (enhanced) stars in the main-sequence (MS) and (or) the RGB, pose a puzzling mystery. Presently, there is still no clear answer to the mechanism(s) that enables such Li depletion (enhancement). One possible explanation comes from the, still controversial, observational evidence of Li underabundances in MS stars hosting planets, and of a positive correlation between the Li abundance and rotational velocity in some RGB stars, which suggests a stellar collision with a planet-like object as a possible solution. In this study we explore this scenario, performing for first time 3D-hydrodynamical simulations of a 0.019 Mo brown dwarf collision with a MS star under different initial conditions. This enables us to gather information about the impact on the physical structure and final Li content in the hosting star.
Comment: 4 pages, 1 figure, presented in Lithium in the Universe: to Be or not to Be?, Frascati, 2019. To be published in MemSAI