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相关论文: New light on the old problem of lithium pre--MS de…

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We show by detailed model computation how much the Pre-Main Sequence (PMS) Lithium depletion depends on the treatment of over-adiabaticity, by taking advantage of the results of new models by Montalb\'an et al., which apply different…

天体物理学 · 物理学 2009-11-10 F. D'Antona , J. Montalban

The Teff location of Pre-Main Sequence (PMS) evolutionary tracks depends on the treatment of over-adiabaticity. Since the convection penetrates into the stellar atmosphere, also the treatment of convection in the modeling of stellar…

天体物理学 · 物理学 2009-11-10 J. Montalban , F. D'Antona , F. Kupka , U. Heiter

Young populations at Z<Zo are being examined to understand the role of metallicity in the first phases of stellar evolution. For the analysis it is necessary to assign mass and age to Pre--Main Sequence (PMS) stars. While it is well known…

天体物理学 · 物理学 2009-11-13 Di Criscienzo , P. Ventura , F. D'Antona

Despite the extensive study of lithium depletion during pre-main-sequence contraction, studies of individual stars show discrepancies between ages determined from the HR diagram and ages determined from lithium depletion (Song et al. 2002,…

太阳与恒星天体物理 · 物理学 2015-05-18 Jennifer C. Yee , Eric L. N. Jensen

Investigating the apparent anomalies in lithium (Li) surface abundance observed in the Sun and young stellar globular clusters holds significant promise for advancing our understanding of the mechanisms influencing Li depletion. This study…

太阳与恒星天体物理 · 物理学 2026-03-11 R. Caballero Navarro , A. García Hernández , J. C. Suárez

We compute rotating 1D stellar evolution models that include a modified temperature gradient in convection zones and criterion for convective instability inspired by rotating 3D hydrodynamical simulations performed with the MUSIC code. In…

太阳与恒星天体物理 · 物理学 2021-10-27 Thomas Constantino , Isabelle Baraffe , Thomas Goffrey , Jane Pratt , Thomas Guillet , Dimitar Vlaykov , Louis Amard

As a step toward a complete theoretical integration of 3D compressible hydrodynamic simulations into stellar evolution, convection at the surface and sub-surface layers of the Sun is re-examined, from a restricted point of view, in the…

太阳与恒星天体物理 · 物理学 2014-11-20 W. David Arnett , Casey Meakin , Patrick A. Young

Recent theoretical work has shown that the pre-main-sequence (PMS) evolution of stars is much more complex than previously envisioned. Instead of the traditional steady, one-dimensional solution, accretion may be episodic and not…

太阳与恒星天体物理 · 物理学 2017-03-08 Masanobu Kunitomo , Tristan Guillot , Taku Takeuchi , Shigeru Ida

The appearance of blue loops in the evolutionary tracks of intermediate-mass core He-burning stars is essential for explaining the observed characteristics of Cepheids. The blue loops for lower mass Cepheids cannot always be reproduced when…

太阳与恒星天体物理 · 物理学 2025-07-23 M. Deka , F. Ahlborn , T. A. M. Braun , A. Weiss

In this review I briefly discuss the theory of pre-main-sequence (PMS) Li depletion in low-mass (0.075<M<1.2 Msun) stars and highlight those uncertain parameters which lead to substantial differences in model predictions. I then summarise…

天体物理学 · 物理学 2015-12-09 R. D. Jeffries

Main sequence, solar-like stars (M < 1.5 Msun) have outer convective envelopes that are sufficiently thick to affect significantly their overall structure. The radii of these stars, in particular, are sensitive to the details of…

太阳与恒星天体物理 · 物理学 2018-12-26 F. Spada , P. Demarque , S. Basu , J. D. Tanner

Evolution of the 7Li abundance in the convection zone of the Sun during different stages of its life time is considered to explain its low photospheric value in comparison with that of the solar system meteorites. Lithium is intensively and…

太阳与恒星天体物理 · 物理学 2017-02-01 F. Thevenin , A. V. Oreshina , V. A. Baturin , A. B. Gorshkov , P. Morel , J. Provost

We investigate lithium depletion in standard stellar models (SSMs) and main sequence (MS) open clusters, and explore the origin of the Li dispersion in young, cool stars of equal mass, age and composition. We first demonstrate that SSMs…

太阳与恒星天体物理 · 物理学 2015-06-18 Garrett Somers , Marc Pinsonneault

We review the application of the one-dimensional Mixing Length Theory (MLT) model of convection in stellar interiors and low-mass stellar evolution. We summarize the history of MLT, present a derivation of MLT in the context of the 1D…

太阳与恒星天体物理 · 物理学 2023-06-01 Meridith Joyce , Jamie Tayar

We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated by…

太阳与恒星天体物理 · 物理学 2017-08-16 I. Baraffe , J. Pratt , T. Goffrey , T. Constantino , D. Folini , M. V. Popov , R. Walder , M. Viallet

Lithium abundances in open clusters are a very effective probe of mixing processes, and their study can help to understand the large depletion of lithium in the Sun. Due to its age and metallicity, the open cluster M67 is especially…

太阳与恒星天体物理 · 物理学 2015-06-04 Giancarlo Pace , Matthieu Castro , Jorge Melendez , Sylvie Theado , Jose-Dias do Nascimento

We examine the physical basis for algorithms to replace mixing-length theory (MLT) in stellar evolutionary computations. Our 321D procedure is based on numerical solutions of the Navier-Stokes equations. These implicit large eddy…

太阳与恒星天体物理 · 物理学 2015-08-19 W. David Arnett , Casey Meakin , Maxime Viallet , Simon W. Campbell , John Lattanzio , Miroslav Mocák

Lithium is predicted, and observed, to be depleted in contracting, low-mass pre main sequence (PMS) stars. Yet these stars reach the zero age main sequence (ZAMS) with a spread in lithium abundance at a given effective temperature that is…

太阳与恒星天体物理 · 物理学 2025-04-28 R. J. Jackson , R. D. Jeffries , E. Tognelli

Lithium abundances in open clusters provide an effective way of probing mixing processes in the interior of solar-type stars and convection is not the only mixing mechanism at work. To understand which mixing mechanisms are occurring in…

太阳与恒星天体物理 · 物理学 2016-05-25 Matthieu Castro , Tharcísyo Duarte , Giancarlo Pace , José Dias do Nascimento

The study of lithium (Li) surface abundance in the Sun and young stellar globular clusters which are seemingly anomalous in present-day scenarios, as well as the influence of rotation and magnetic braking (MB) on its depletion during…

太阳与恒星天体物理 · 物理学 2020-07-01 R. Caballero Navarro , A. García Hernández , A. Ayala , J. C. Suárez
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