2002/06/19 by S. Turcotte, Sylvain Turcotte · 24 citations
Physics and Astronomy · #Accretion (finance) #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Mixing (physics) #Physics #Quantum mechanics #Stars #Stellar, planetary, and galactic studies #T Tauri star #astro-ph
paper · pdf · doi:10.1086/342054
published in The Astrophysical Journal 573(2), L129-L132 (IOP Publishing) · To appear in Astrophysical Journal Letters. 4 pages, 2 fgures
arxiv created 2002/06/19 · openalex publication_date 2002/07/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Strong evidence for deep mixing has been uncovered for slowly rotating F and A stars of the main sequence. As the accretion/diffusion model for the formation of λ Bootis stars is heavily dependent on mixing in superficial regions, such deep mixing may have important repercussions on our understanding of these stars. It is shown that deep mixing at a level similar to that of FmAm stars increases the amount of matter that needs to be accreted by the stars with respect to the standard models by some 3 orders of magnitude. It is also shown that significantly larger accretion rates have to be maintained, as high as 10 -11 M ☉ yr -1 , to prevent meridional circulation from canceling the effect of accretion. The existence of old (≈1 Gyr) stars is not a likely outcome of the present models for accretion/diffusion with or without deep mixing. It is argued that λ Bootis stars are potentially very good diagnostics of mixing mechanisms in moderately fast rotators.