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Extending our recent studies of two-dimensional stellar convection to 3D, we compare three-dimensional hydrodynamic simulations to identically set-up two-dimensional simulations, for a realistic pre-main sequence star. We compare…

Solar and Stellar Astrophysics · Physics 2020-07-01 J. Pratt , I. Baraffe , T. Goffrey , C. Geroux , T. Constantino , D. Folini , R. Walder

Context: We study the impact of two-dimensional spherical shells on compressible convection. Realistic profiles for density and temperature from a one-dimensional stellar evolution code are used to produce a model of a large stellar…

Solar and Stellar Astrophysics · Physics 2016-10-05 J. Pratt , I. Baraffe , T. Goffrey , C. Geroux , M. Viallet , D. Folini , T. Constantino , M. Popov , R. Walder

1D stellar evolution calculations produce uncertain predictions for quantities like the age, core mass, core compactness, and nucleo-synthetic yields; a key source of uncertainty is the modeling of interfaces between regions that are…

There is strong observational evidence that the convective cores of intermediate-mass and massive main sequence stars are substantially larger than those predicted by standard stellar-evolution models. However, it is unclear what physical…

Solar and Stellar Astrophysics · Physics 2024-08-20 R. Andrassy , G. Leidi , J. Higl , P. V. F. Edelmann , F. R. N. Schneider , F. K. Roepke

Because Cepheid variable stars have long been used as a cosmic benchmark, the accuracy of stellar evolution models for Cepheids have wide-reaching effects. Our goal is to provide a detailed multi-dimensional picture of hydrodynamic…

Solar and Stellar Astrophysics · Physics 2025-06-25 Maxime Stuck , Jane Pratt , Isabelle Baraffe , Joyce Ann Guzik , Mary-Geer Dethero , Dimitar Vlaykov , Tom Goffrey , Arthur Le Saux

Observations indicate that the convective cores of stars must ingest a substantial amount of material from the overlying radiative zone, but the extent of this mixing and the mechanism which causes it remain uncertain. Recently, Anders et…

Solar and Stellar Astrophysics · Physics 2022-05-11 Adam S. Jermyn , Evan H. Anders , Daniel Lecoanet , Matteo Cantiello

Most stars host convection zones in which heat is transported directly by fluid motion, but the behavior of convective boundaries is not well understood. Here we present 3D numerical simulations which exhibit penetration zones: regions…

Solar and Stellar Astrophysics · Physics 2022-03-14 Evan H. Anders , Adam S. Jermyn , Daniel Lecoanet , Benjamin P. Brown

We perform Large eddy simulations of turbulent compressible convection in stellar-type convection zones by solving the Navi\'{e}r-Stokes equations in three dimensions. We estimate the extent of penetration into the stable layer above a…

Astrophysics · Physics 2009-06-23 Partha S. Pal , Harinder P. Singh , Kwing L. Chan , M. P. Srivastava

We present 3-D hydrodynamical simulations of core convection with a stably stratified envelope of a \unit{25}{\Msun} star in the early phase of the main-sequence. We use the explicit gas-dynamics code \code{PPMstar} which tracks two fluids…

Solar and Stellar Astrophysics · Physics 2024-08-13 Huaqing Mao , Paul Woodward , Falk Herwig , Pavel A. Denissenkov , Simon Blouin , William Thompson , Benjamin McDermott

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

The treatment of convection remains a major weakness in the modelling of stellar evolution with one-dimensional (1D) codes. The ever increasing computing power makes now possible to simulate in 3D part of a star for a fraction of its life,…

Solar and Stellar Astrophysics · Physics 2024-06-03 C. Georgy , F. Rizzuti , R. Hirschi , V. Varma , W. D. Arnett , C. Meakin , M. Mocak , A. StJ. Murphy , T. Rauscher

Theoretical descriptions of convective overshooting often rely on a one-dimensional parameterization of the flow called the filling factor for convection. Several definitions of the filling factor have been developed, based on: (1) the…

Solar and Stellar Astrophysics · Physics 2024-12-04 M. -G. Dethero , J. Pratt , D. G. Vlaykov , I. Baraffe , T. Guillet , T. Goffrey , A. Le Saux , A. Morison

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

(Abridged) We describe the results of three-dimensional (3D) numerical simulations designed to study turbulent convection in the stellar interiors, and compare them to stellar mixing-length theory (MLT). Simulations in 2D are significantly…

Astrophysics · Physics 2011-02-11 Casey A. Meakin , David Arnett

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the…

Solar and Stellar Astrophysics · Physics 2016-05-17 Joyce A. Guzik , T. H. Morgan , N. J. Nelson , C. Lovekin , K. Kosak , I. N. Kitiashvili , N. N. Mansour , A. Kosovichev

This paper describes the first steps of development of a new multidimensional time implicit code devoted to the study of hydrodynamical processes in stellar interiors. The code solves the hydrodynamical equations in spherical geometry and…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 M. Viallet , I. Baraffe , R. Walder

3D hydrodynamics models of deep stellar convection exhibit turbulent entrainment at the convective-radiative boundary which follows the entrainment law, varying with boundary penetrability. We implement the entrainment law in the 1D Geneva…

Solar and Stellar Astrophysics · Physics 2021-03-24 L. J. A. Scott , R. Hirschi , C. Georgy , W. D. Arnett , C. Meakin , E. A. Kaiser , S. Ekström , N. Yusof

We perform two- (2D) and three-dimensional (3D) hydrodynamics simulations of convective oxygen shell-burning that takes place deep inside a massive progenitor star of a core-collapse supernova. Using one dimensional (1D) stellar evolution…

Solar and Stellar Astrophysics · Physics 2019-08-14 Takashi Yoshida , Tomoya Takiwaki , Kei Kotake , Koh Takahashi , Ko Nakamura , Hideyuki Umeda

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

Convection is ubiquitous in stars and occurs under many different conditions. Here we explore convection in main-sequence stars through two lenses: dimensionless parameters arising from stellar structure and parameters which emerge from the…

Solar and Stellar Astrophysics · Physics 2022-08-31 Adam S. Jermyn , Evan H. Anders , Daniel Lecoanet , Matteo Cantiello
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