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Related papers: A study of convective core overshooting as a funct…

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Our understanding of stellar structure and evolution coming from one-dimensional (1D) stellar models is limited by uncertainties related to multi-dimensional processes taking place in stellar interiors. 1D models, however, can now be tested…

Solar and Stellar Astrophysics · Physics 2022-08-17 F. Rizzuti , R. Hirschi , C. Georgy , W. D. Arnett , C. Meakin , A. StJ. Murphy

Stellar evolution calculations have had great success reproducing the observed atmospheric properties of different classes of stars. Recent detections of g-mode pulsations in evolved He burning stars allow a rare comparison of their…

Solar and Stellar Astrophysics · Physics 2015-05-27 Jan-Torge Schindler , Elizabeth M. Green , W. David Arnett

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

Massive ($M >30\,$M$_{\odot}$) stars exhibit luminosities that are near the Eddington-limit for electron scattering causing the increase in opacity associated with iron at $T\approx180,000\,$K to trigger supersonic convection in their outer…

Solar and Stellar Astrophysics · Physics 2020-10-21 William Schultz , Lars Bildsten , Yan-Fei Jiang

State-of-the-art one-dimensional (1D) stellar evolution codes rely on simplifying assumptions, such as mixing length theory, in order to describe superadiabatic convection. As a result, 1D stellar structure models do not correctly recover…

Solar and Stellar Astrophysics · Physics 2019-08-07 Andreas Christ Sølvsten Jørgensen , Achim Weiss

A major weakness in one-dimensional (1D) stellar structure and evolution modeling is the simplified treatment of convection, which leads to erroneous near-surface stratification and considerable uncertainties in predicted effective…

The era of detailed asteroseismic analyses opened by space missions such as CoRoT and $\textit{Kepler}$ has highlighted the need for stellar models devoid of numerical inaccuracies, in order to be able to diagnose which physical aspects are…

Solar and Stellar Astrophysics · Physics 2014-09-24 Maurice Gabriel , Arlette Noels , Josefina Montalban , Andrea Miglio

Low-mass models of M-dwarfs that undergo the convective kissing instability fluctuate in luminosity and temperature resulting in a gap in the main sequence that is observed in the $Gaia$ data. During this instability, the models have…

Solar and Stellar Astrophysics · Physics 2023-09-15 Santana Mansfield , Pavel Kroupa

We present the first hydrodynamic, multi-dimensional simulations of He-shell flash convection. Specifically, we investigate the properties of shell convection at a time immediately before the He- luminosity peak during the 15th thermal…

Astrophysics · Physics 2009-11-11 Falk Herwig , Bernd Freytag , Robert M. Hueckstaedt , Francis X. Timmes

The dynamics and thermal structure of the surface layers of stars with outer convection zones can be studied in some detail by means of numerical simulations of time-dependent compressible convection. In an effort to investigate the…

Astrophysics · Physics 2007-05-23 Matthias Steffen

Based on detailed 2D and 3D numerical radiation-hydrodynamics (RHD) simulations of time-dependent compressible convection, we have studied the dynamics and thermal structure of the convective surface layers of a prototypical late-type…

Astrophysics · Physics 2009-11-07 H. -G. Ludwig , F. Allard , P. H. Hauschildt

We apply the mathematical formalism of vector spherical harmonics decomposition to convective stellar velocity fields from multi-dimensional hydrodynamics simulations, and show that the resulting power spectra furnish a robust and stable…

Solar and Stellar Astrophysics · Physics 2015-06-19 Emmanouil Chatzopoulos , Carlo Graziani , Sean M. Couch

High-resolution images of the solar surface show a granulation pattern of hot rising and cooler downward-sinking material -- the top of the deep-reaching solar convection zone. Convection plays a role for the thermal structure of the solar…

Solar and Stellar Astrophysics · Physics 2011-12-14 Bernd Freytag , Matthias Steffen , Hans-Günter Ludwig , Sven Wedemeyer-Böhm , Werner Schaffenberger , Oskar Steiner

We compare evolved stellar models, which match Procyons mass and position in the HR diagram, to current ground-based asteroseismic observations. Diffusion of helium and metals along with two conventional core overshoot descriptions and the…

Solar and Stellar Astrophysics · Physics 2015-06-19 D. B. Guenther , P. Demarque , M Gruberbauer

We present the first three-dimensional (3D), hydrodynamic simulations of the core convection zone (CZ) and extended radiative zone spanning from 1% to 90% of the stellar radius of an intermediate mass (3 $\mathrm{M}_\odot$) star. This…

Solar and Stellar Astrophysics · Physics 2019-05-01 P. V. F. Edelmann , R. P. Ratnasingam , M. G. Pedersen , D. M. Bowman , V. Prat , T. M. Rogers

Stellar convection is a non-local process responsible for the transport of heat and chemical species. It can lead to enhanced mixing through convective overshooting and excitation of internal gravity waves (IGWs) at convective boundaries.…

Solar and Stellar Astrophysics · Physics 2022-06-08 D. G. Vlaykov , I. Baraffe , T. Constantino , T. Goffrey , T. Guillet , A. Le Saux , A. Morison , J. Pratt

We have developed a three-dimensional radiation hydrodynamics code to simulate the interaction of convection and radial pulsation in classical variable stars. One key goal is the ability to carry these simulations to full amplitude in order…

Solar and Stellar Astrophysics · Physics 2015-06-16 Chris M. Geroux , Robert G. Deupree

Context. The surface structures and dynamics of cool stars are characterized by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims. We used realistic three-dimensional radiative hydrodynamical…

Solar and Stellar Astrophysics · Physics 2018-03-14 A. Chiavassa , L. Casagrande , R. Collet , Z. Magic , L. Bigot , F. Thevenin , M. Asplund

The evolution of stars born with a convective core is highly dependent on the efficiency and extent of near core mixing processes, which effectively increases both the core mass and main-sequence lifetime. We investigate to what extent…

Solar and Stellar Astrophysics · Physics 2018-07-04 M. G. Pedersen , C. Aerts , P. I. Pápics , T. M. Rogers

We simulate stellar convection at high Reynolds number (Re$\lesssim$7000) with causal time stepping but no explicit viscosity. We use the 3D Euler equations with shock capturing (Colella & Woodward 1984). Anomalous dissipation of turbulent…

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