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

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In this paper we describe our convective hydrocodes for radial stellar pulsation. We adopt the Kuhfuss (1986) model of convection, reformulated for the use in stellar pulsation hydrocodes. Physical as well as numerical assumptions of the…

Astrophysics · Physics 2008-10-13 R. Smolec , P. Moskalik

We construct a semi-analytical model that describes the convective core mass evolution of massive stars experiencing mass loss during the main-sequence stage. We first conduct a suite of 1D stellar evolution calculations to build insight…

Solar and Stellar Astrophysics · Physics 2024-09-04 Minori Shikauchi , Ryosuke Hirai , Ilya Mandel

We explore the three-dimensional properties of convective, luminous ($L\approx10^{4.5}-10^{5}L_\odot$), Hydrogen-rich envelopes of Red Supergiants (RSGs) based on radiation hydrodynamic simulations in spherical geometry using…

Solar and Stellar Astrophysics · Physics 2022-05-04 Jared A. Goldberg , Yan-Fei Jiang , Lars Bildsten

The scale length over which convection mixes mass in a star can be calculated as the inverse of the vertical derivative of the unidirectional (up or down) mass flux. This is related to the mixing length in the mixing length theory of…

Solar and Stellar Astrophysics · Physics 2015-05-27 Regner Trampedach , Robert F. Stein

We study the dynamics associated with the extension of turbulent convective motions from a convection zone (CZ) into a stable region (RZ) that lies below the latter. For that purpose, we have run a series of three-dimensional direct…

Solar and Stellar Astrophysics · Physics 2019-01-16 Lydia Korre , Pascale Garaud , Nicholas Brummell

Regions of stellar and planetary interiors that are unstable according to the Schwarzschild criterion, but stable according to the Ledoux criterion, are subject to a form of oscillatory double-diffusive (ODD) convection often called…

Solar and Stellar Astrophysics · Physics 2015-01-22 Toby S. Wood , Pascale Garaud , Stephan Stellmach

We present the first detailed three-dimensional (3D) hydrodynamic implicit large eddy simulations of turbulent convection of carbon burning in massive stars. Simulations begin with radial profiles mapped from a carbon burning shell within a…

Solar and Stellar Astrophysics · Physics 2017-08-02 Andrea Cristini , Casey Meakin , Raphael Hirschi , David Arnett , Cyril Georgy , Maxime Viallet

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

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

We present a detailed study of the small frequency separations as diagnostics of the mass of the convective core and evolutionary stage of solar-type stars. We demonstrate how the small separations can be combined to provide sensitive tests…

Astrophysics · Physics 2009-11-11 Anwesh Mazumdar , Sarbani Basu , Braxton L. Collier , Pierre Demarque

We present a framework to simultaneously constrain the values and uncertainties of the strength of convective core overshooting, metallicity, extinction, distance, and age in stellar populations. We then apply the framework to archival…

We study convective overshooting by means of local 3D convection calculations. Using a mixing length model of the solar convection zone (CZ) as a guide, we determine the Coriolis number (Co), which is the inverse of the Rossby number, to be…

Astrophysics · Physics 2015-06-24 P. J. Käpylä , M. J. Korpi , M. Stix , I. Tuominen

Two dimensional hydrodynamical simulations of convective oxygen burning shell in the presupernova evolution of a 20 solar-mass star are extended to later times. We used the VULCAN code to simulate longer evolution times than previously…

Astrophysics · Physics 2009-10-31 S. M. Asida , David Arnett

We present numerical simulations of convective overshoot in a two-dimensional model of the solar equatorial plane. The simulated domain extends from 0.001 R_sun to 0.93 R_sun, spanning both convective and radiative regions. We show that…

Astrophysics · Physics 2008-11-26 Tamara M. Rogers , Gary A. Glatzmaier

The overall evolution of low-mass stars is heavily influenced by the processes occurring in the stellar interior. In particular, mixing processes in convectively unstable zones and overshooting regions affect the resulting observables and…

Solar and Stellar Astrophysics · Physics 2015-05-27 V. Silva Aguirre , J. Ballot , A. M. Serenelli , A. Weiss

In stars and planets natural processes heat convective flows in the bulk of a convective region rather than at hard boundaries. By characterizing how convective dynamics are determined by the strength of an internal heating source we can…

Fluid Dynamics · Physics 2024-04-16 Whitney T. Powers , Evan H. Anders , Benjamin P. Brown

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

Supermassive stars are Population III stars with masses exceeding $10^4\,M_{\odot}$ that could be the progenitors of the first supermassive black holes. Their interiors are in a regime where radiation pressure dominates the equation of…

Solar and Stellar Astrophysics · Physics 2023-03-29 Simon Blouin , Huaqing Mao , Tyrone E. Woods , Pavel Denissenkov , Paul R. Woodward , Falk Herwig

Overshooting and semiconvection are among the most uncertainties in the evolution of massive stars. Complete mixing over a certain distance beyond the convective boundary (Stothers \& Chin 1985) and an exponentially decaying diffusion…

Solar and Stellar Astrophysics · Physics 2019-01-16 Yan Li , Xing-hao Chen , Hai-liang Chen

Our poor understanding of the boundaries of convective cores generates large uncertainties on the extent of these cores and thus on stellar ages. Our aim is to use asteroseismology to consistently measure the extent of convective cores in a…

Solar and Stellar Astrophysics · Physics 2016-04-20 S. Deheuvels , I. Brandão , V. Silva Aguirre , J. Ballot , E. Michel , M. S. Cunha , Y. Lebreton , T. Appourchaux