English
Related papers

Related papers: The Mass Mixing Length in Convective Stellar Envel…

200 papers

The transport of energy through convection is important during many stages of stellar evolution, and is best studied in our Sun or giant evolved stars. Features that are attributed to convection are found on the surface of massive red…

Solar and Stellar Astrophysics · Physics 2024-09-16 W. Vlemmings , T. Khouri , B. Bojnordi Arbab , E. De Beck , M. Maercker

We perform two-dimensional numerical simulations of core convection for zero-age-main-sequence stars covering a mass range from 3 $M_\odot$ to 20 $M_\odot$. The simulations are performed with the fully compressible time-implicit code MUSIC.…

Solar and Stellar Astrophysics · Physics 2023-01-18 I. Baraffe , J. Clarke , A. Morison , D. G. Vlaykov , T. Constantino , T. Goffrey , T. Guillet , A. Le Saux , J. Pratt

Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and…

Convective overshoot mixing is a critical ingredient of stellar structure models, but is treated in most cases by ad hoc extensions of the mixing-length theory for convection. Advanced theories which are both more physical and numerically…

Solar and Stellar Astrophysics · Physics 2022-11-16 Felix Ahlborn , Friedrich Kupka , Achim Weiss , Martin Flaskamp

Convection and rotation are both key processes in stellar evolution modelling. While standard mixing-length theory (MLT) provides a widely used modelling of convection, it neglects the effects of rotation on convective transport. We…

Solar and Stellar Astrophysics · Physics 2026-04-02 Poojan Agrawal , Aaron Dotter , Conny Aerts , Leïla Bessila , Stéphane Mathis

Continued progress in observational stellar astrophysics requires a deep understanding of the underlying convection dynamics. We present results of realistic 3D radiative hydrodynamic simulations of the outer layers of a moderate mass star…

Solar and Stellar Astrophysics · Physics 2016-04-27 Irina N. Kitiashvili , Alexander G. Kosovichev , Nagi N. Mansour , Alan A. Wray

(abridged) Context: Rotation is thought to influence the size of convective eddies and the efficiency of convective energy transport in the deep convection zones of stars. Rotationally constrained convection has been invoked to explain the…

Solar and Stellar Astrophysics · Physics 2023-10-20 Petri J. Käpylä

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…

Solar and Stellar Astrophysics · Physics 2017-08-16 I. Baraffe , J. Pratt , T. Goffrey , T. Constantino , D. Folini , M. V. Popov , R. Walder , M. Viallet

In this paper, four sets of evolutionary models are computed with different values of the mixing length parameter $\alpha_{\rm p}$ and the overshooting parameter $\delta_{\rm ov}$. The properties of the convective cores and the convective…

Solar and Stellar Astrophysics · Physics 2015-05-14 Jin Jie , Chunhua Zhu , Guoliang Lv

Results of realistic simulations of solar surface convection on the scale of supergranules (96 Mm wide by 20 Mm deep) are presented. The simulations cover only 10% of the geometric depth of the solar convection zone, but half its pressure…

Astrophysics · Physics 2008-11-05 R. F. Stein , A. Nordlund , D. Georgobiani , D. Benson , W. Schaffenberger

A monomodal model for stellar and planetary convection is derived for the magnitude of the rms velocity, degree of superadiabaticity, and characteristic length scale as a function of rotation rate as well as with thermal and viscous…

Solar and Stellar Astrophysics · Physics 2019-04-03 Kyle C. Augustson , Stéphane Mathis

The convective envelopes of cool main-sequence stars harbour magnetic fields with a complex global and local structure. These fields affect the near-surface convection and the outer stellar atmospheres in many ways and are responsible for…

Solar and Stellar Astrophysics · Physics 2015-09-02 Benjamin Beeck , Manfred Schüssler , Robert H. Cameron , Ansgar Reiners

An attempt at understanding downward overshooting in the convective envelopes of post-main-sequence stars has been made on the basis of three-dimensional large-eddy simulations, using artificially modified OPAL opacity and taking into…

Solar and Stellar Astrophysics · Physics 2016-03-08 Chun-Lin Tian , Li-Cai Deng , Kwing-Lam Chan

This work investigates the properties of convection in stars with particular emphasis on entrainment across the upper convective boundary (CB). Idealised simulations of turbulent convection in the O-burning shell of a massive star are…

Solar and Stellar Astrophysics · Physics 2016-11-03 Samuel Jones , Robert Andrassy , Stou Sandalski , Austin Davis , Paul Woodward , Falk Herwig

Surface granulation of the Sun is primarily a consequence of thermal transport in the outer 1 % of the radius. Its typical scale of about 1 - 2 Mm is set by the balance between convection, free-streaming radiation, and the strong density…

Solar and Stellar Astrophysics · Physics 2015-06-18 Shravan M. Hanasoge , Katepalli R. Sreenivasan

The near-surface layers of cool main-sequence stars are structured by convective flows, which are overshooting into the atmosphere. The flows and the associated spatio-temporal variations of density and temperature affect spectral line…

Solar and Stellar Astrophysics · Physics 2013-08-27 Benjamin Beeck , Robert H. Cameron , Ansgar Reiners , Manfred Schüssler

Double-diffusive convection refers to mixing where the effects of thermal and composition gradients compete to determine the stability of a fluid. In addition to the familiar fast convective instability, such fluids exhibit the slow, direct…

Astrophysics · Physics 2015-06-24 Scott A. Grossman , Ronald E. Taam

The excitation rate P of solar p-modes is computed with a model of stochatic excitation which involves constraints on the averaged properties of the solar turbulence. These constraints are obtained from a 3D simulation. Resulting values for…

Astrophysics · Physics 2007-05-23 R. Samadi , M. J. Goupil , Y. Lebreton , A. Nordlund , F. Baudin

The convective envelopes of solar-type stars and the convective cores of intermediate- and high-mass stars share boundaries with stable radiative zones. Through a host of processes we collectively refer to as "convective boundary mixing"…

Solar and Stellar Astrophysics · Physics 2023-04-18 Evan H. Anders , May G. Pedersen

Based on detailed 2D numerical radiation hydrodynamics (RHD) calculations of time-dependent compressible convection, we have studied the dynamics and thermal structure of the convective surface layers of solar-type stars. The RHD models…

Astrophysics · Physics 2007-05-23 H. -G. Ludwig , B. Freytag , M. Steffen