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Related papers: Convective core entrainment in 1D main sequence st…

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The treatment of mixing processes is still one of the major uncertainties in 1D stellar evolution models. This is mostly due to the need to parametrize and approximate aspects of hydrodynamics in hydrostatic codes. In particular, the effect…

Solar and Stellar Astrophysics · Physics 2017-08-02 Philipp V. F. Edelmann , Friedrich K. Roepke , Raphael Hirschi , Cyril Georgy , Samuel Jones

Turbulent friction in convective regions in stars and planets is one of the key physical mechanisms that drive the dissipation of the kinetic energy of tidal flows in their interiors and the evolution of their systems. This friction acts…

Solar and Stellar Astrophysics · Physics 2016-07-20 Stéphane Mathis , Pierre Auclair-Desrotour , Mathieu Guenel , Florian Gallet , Christophe Le Poncin-Lafitte

In this work we generalize the notion of convective inhibition to apply in cases where there is an infinite reservoir of condensible species (i.e., an ocean). We propose a new model for the internal structure and thermal evolution of…

Earth and Planetary Astrophysics · Physics 2022-09-07 Steve Markham , Dave Stevenson , Tristan Guillot

Context. Light elements and nitrogen surface abundances together can constrain the mixing efficiencies in massive stars on the main sequence, because moderate mixing at the surface leads to a depletion of light elements but only later to an…

Classical Wolf-Rayet (cWR) stars are evolved massive stars that have lost most of their H envelope and exhibit dense, extended atmospheres with strong, line-driven winds. Accurately modeling wind launching from optically thick layers…

The absorption of light or radiation drives turbulent convection inside stars, supernovae, frozen lakes and the Earth's mantle. In these contexts, the goal of laboratory and numerical studies is to determine the relation between the…

Fluid Dynamics · Physics 2021-01-08 Simon Lepot , Sébastien Aumaître , Basile Gallet

We present numerical results on three-dimensional (3D) hydrodynamic core-collapse simulations of an $11.2 M_{\odot}$ star. By comparing one-(1D) and two-dimensional(2D) results with those of 3D, we study how the increasing spacial…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Tomoya Takiwaki , Kei Kotake , Yudai Suwa

Direct collapse of supermassive stars is a possible pathway to form supermassive black hole seeds at high redshifts. Whereas previous three-dimensional (3D) simulations demonstrate that supermassive stars form via rapid mass accretion,…

Astrophysics of Galaxies · Physics 2023-07-05 Kazutaka Kimura , Takashi Hosokawa , Kazuyuki Sugimura , Hajime Fukushima

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

Convection plays a key role in the evolution of stars due to energy transport and mixing of composition. Despite its importance, this process is still not well understood. One longstanding conundrum in all 1D stellar evolution codes is the…

Solar and Stellar Astrophysics · Physics 2020-01-08 Etienne A. Kaiser , Raphael Hirschi , W. David Arnett , Andrea Cristini , Cyril Georgy , Laura J. A. Scott

Convection of an internally heated fluid, confined between top and bottom plates of equal temperature, is studied by direct numerical simulation in two and three dimensions. The unstably stratified upper region drives convection that…

Fluid Dynamics · Physics 2016-06-30 David Goluskin , Erwin P. van der Poel

Degenerate ignition of helium in low-mass stars at the end of the red giant branch phase leads to dynamic convection in their helium cores. One-dimensional (1D) stellar modeling of this intrinsically multi-dimensional dynamic event is…

Solar and Stellar Astrophysics · Physics 2015-05-18 Miroslav Mocak , Simon W. Campbell , Ewald Mueller , Konstantinos Kifonidis

Atomic diffusion has been recognized as an important process that has to be considered in any computations of stellar models. In solar-type and cooler stars, this process is dominated by gravitational settling, which is now included in most…

Solar and Stellar Astrophysics · Physics 2012-10-17 S. Theado , G. Alecian , F. LeBlanc , S. Vauclair

The common envelope (CE) phase plays a key role in the formation of binary compact object systems. Its final outcome strongly depends on the envelope binding energy, but this quantity is often estimated using fitting formulas that are not…

Three-dimensional (3D) hydrodynamic simulations of shell oxygen burning (Meakin and Arnett 2007) exhibit bursty, recurrent fluctuations in turbulent kinetic energy. These are shown to be due to a global instability in the convective region,…

Solar and Stellar Astrophysics · Physics 2015-05-20 W. David Arnett , Casey Meakin

The detection of mixed oscillation modes offers a unique insight into the internal structure of core helium burning (CHeB) stars. The stellar structure during CHeB is very uncertain because the growth of the convective core, and/or the…

Solar and Stellar Astrophysics · Physics 2015-07-06 Thomas Constantino , Simon W. Campbell , Joergen Christensen-Dalsgaard , John C. Lattanzio , Dennis Stello

Recently 3D hydrodynamical simulations of stellar surface convection have become feasible thanks to advances in computer technology and efficient numerical algorithms. Available observational diagnostics indicate that these models are…

Astrophysics · Physics 2007-05-23 Martin Asplund , Remo Collet

The dynamic behavior of crystals in convecting fluids determines how magma bodies solidify. In particular, it is often important to estimate how long crystals stay in suspension in the host liquid before being deposited at its bottom (or…

Geophysics · Physics 2022-05-31 Vojtěch Patočka , Nicola Tosi , Enrico Calzavarini

Inertial modes have been observed on the Sun at low longitudinal wavenumbers. These modes probe the dynamics and structure of the solar convection zone down to the tachocline. While linear analysis allows the complex eigenfrequencies and…

Solar and Stellar Astrophysics · Physics 2023-05-31 J. Philidet , L. Gizon

Context. The red supergiant (RSG) Betelgeuse is an irregular variable star. Convection may play an important role in understanding this variability. Interferometric observations can be interpreted using sophisticated simulations of stellar…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Chiavassa , X. Haubois , J. S. Young , B. Plez , E. Josselin , G. Perrin , B. Freytag