Abstract
Based on radiation hydrodynamics modeling of stellar convection zones, a diffusion scheme has been devised describing the downward penetration of convective motions beyond the Schwarzschild boundary (overshoot) into the radiative interior. This scheme of exponential diffusive overshoot has already been successfully applied to AGB stars. Here we present an application to the Sun in order to determine the time scale and depth extent of this additional mixing, i.e. diffusive overshoot at the base of the convective envelope. We calculated the associated destruction of lithium during the evolution towards and on the main-sequence. We found that the slow-mixing processes induced by the diffusive overshoot may lead to a substantial depletion of lithium during the Sun's main-sequence evolution.
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Alexander, D.R. and Ferguson, J.W.: 1994, ‘Low-temperature Rosseland opacities', ApJ 437, 879–891.
Anders, E. and Grevesse, N.: 1989, ‘Abundances of the elements: Meteoritic and solar', Geochim Cosmochim. Acta 53, 197–214.
Blöcker, T.: 1995, ‘Stellar evolution of low and intermediate mass stars: I. Mass loss on the AGB and its consequences for stellar evolution', A&A 297, 727–738.
Blöcker, T.: 1998, ‘Theory of AGB evolution', Space Science Reviews, in press.
Bochsler, P, Geiss, J. and Maeder, A.: 1990, ‘The abundance of He-3 in the solar wind — A constraint for models of solar evolution', Solar Phys. 128, 203–215.
Böhm-Vitense, E.: 1958, ‘Über die Wasserstoffkonvektionszone in Sternen verschiedener Effek tivtemperaturen und Leuchtkrafte', Z. f. Astrophys. 46, 108–143.
Chaboyer, B.: 1998, ‘Internal rotation, mixing and lithium abundances', in IAU Symp. 185, New Eyes to See Inside the Sun and Stars, in press.
Delyannis, C.P. and Pinsonneault, M.H: 1997, ‘110 Herculis: A Possible Prototype for Simultaneous Lithium and Beryllium Depletion, and Implications for Stellar Interiors’ ApJ 488, 836–840.
Herwig, F., Blöcker, T., Schönberner, D. and El Eid, M.: 1997, ‘Stellar evolution of low and intermediate mass stars: IV. Hydrodynamically-based overshoot and nucleosynthesis in AGB stars’ A&A 324, L81-L84.
Freytag, B., Ludwig, H.-G. and Steffen, M.: 1996, ‘Hydrodynamical models of stellar convection The role of overshoot in DA white dwarfs, A-type stars, and the Sun', A&A 313, 497–516.
Iglesias, C.A. and Rogers, F.J.: 1996, ‘Updated Opal Opacities', ApJ 464, 943–953.
Iglesias, C.A., Rogers, F.J., and Wilson, B.G.: 1992, ‘Spin-orbit interaction effects on the Rossclane mean opacity', ApJ 397, 717–728.
Jones, B.F., Fischer, D., Shetrone, M., Soderblom, D.R.: 1997, ‘The evolution of the lithium abundances of solar-type stars', AJ 114, 352–362.
Langer, N., Fricke, K.J., and El Eid, M.: 1985, ‘Evolution of massive stars with semiconvective diffusion’ A&A 145, 179–191.
Martin, C.L. and Claret, A.: 1996 ‘Stellar models with rotation: an exploratory application to premain sequence Lithium Depletion', A&A 306, 408–416.
Michaud, G.: 1986, ‘The lithium abundance gap in the Hyades F stars — The signature of diffusion', ApJ 302, 650–655.
Pinsonneault, M.H.: 1997 ‘Mixing in stars', ARA&A 35, 557–605.
Pinsonneault, M.H., Deliyannis, C.P., Demarque, P.: 1992 ‘Evolutionary models of halo stars with rotation: II.Effects of metallicity on lithium depletion, and possible implications for the primordial lithium abundance’ ApJS 78, 179–203.
Press, W.H.: 1981, ‘Radiative and other effects from internal waves in solar and stellar interiors', ApJ 245, 286–303.
Stephens, A., Boesgaard, A.M., King, J.R. and Deliyannis, C.P.: 1997, ‘Beryllium in Lithium-deficient F and G Stars', ApJ 491, 339–358.
Schramm, D.N., Steigmann, G., Dearborn, D.S.P.: 1992, ‘Main-sequence mass loss and the lithium dip’ ApJ 359, L55-L58.
Zahn, J.-P.: 1992, ‘Circulation and turbulence in rotating stars', A&A 265, 115–132.
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Blöcker, T., Holweger, H., Freytag, B. et al. Lithium Depletion in the Sun: A Study of Mixing Based on Hydrodynamical Simulations. Space Science Reviews 85, 105–112 (1998). https://doi.org/10.1023/A:1005192804708
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DOI: https://doi.org/10.1023/A:1005192804708