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The helioseismic observations of the internal rotation profile of the Sun raise questions about the two-dimensional (2D) nature of the transport of angular momentum in stars. Here we derive a convective prescription for axisymmetric (2D)…

Solar and Stellar Astrophysics · Physics 2015-06-15 P. Lesaffre , S. M. Chitre , A. T. Potter , C. A. Tout

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…

Thermohaline convection is a standard chemical mixing process in stellar interiors, yet its mixing efficiency is not fully settled. Competing theories predict turbulent diffusion coefficients, $D_\mu$, that can differ by orders of…

Solar and Stellar Astrophysics · Physics 2026-05-06 Valentin A. Skoutnev

Our knowledge of stellar evolution is driven by one-dimensional (1D) simulations. 1D models, however, are severely limited by uncertainties on the exact behaviour of many multi-dimensional phenomena occurring inside stars, affecting their…

Solar and Stellar Astrophysics · Physics 2023-05-26 F. Rizzuti , R. Hirschi , W. D. Arnett , C. Georgy , C. Meakin , A. StJ. Murphy , T. Rauscher , V. Varma

The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in…

Solar and Stellar Astrophysics · Physics 2015-06-23 Yang Gao , Haitao Xu , Chung K. Law

The process referred to as "semi-convection" in astrophysics and "double-diffusive convection in the diffusive regime" in Earth and planetary sciences, occurs in stellar and planetary interiors in regions which are stable according to the…

Solar and Stellar Astrophysics · Physics 2015-06-03 Giovanni M. Mirouh , Pascale Garaud , Stephan Stellmach , Adrienne L. Traxler , Toby S. Wood

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

The helioseimic investigation shows that the convective overshooting can penetrate $0.37H_P$ to the location where the temperature is $2.5\times10^6 K$ which is the typical temperature of the reaction $Li^7(p,\alpha)He^4$. This indicates…

Solar and Stellar Astrophysics · Physics 2013-07-16 Q. S. Zhang

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

Convective overshooting in super asymptotic giant branch stars has been suggested to lead to the formation of hybrid white dwarfs with carbon-oxygen cores and oxygen-neon mantles. As the white dwarf cools, this core-mantle configuration…

Solar and Stellar Astrophysics · Physics 2019-05-01 Josiah Schwab , Pascale Garaud

The complex evolution of turbulent mixing in Rayleigh-Taylor convection is studied in terms of eddy diffusiviy models for the mean temperature profile. It is found that a non-linear model, derived within the general framework of Prandtl…

Chaotic Dynamics · Physics 2015-05-18 G. Boffetta , F. De Lillo , S. Musacchio

Tropical convective clouds evolve over a wide range of temporal and spatial scales, and this makes them difficult to simulate numerically. Here, we propose that their statistical properties can be derived within a simplified…

Atmospheric and Oceanic Physics · Physics 2019-01-09 Timothy J. Garrett , Ian B. Glenn , Steven K. Krueger

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…

Astrophysics · Physics 2007-05-23 Ralf Klessen

We study turbulent convection during the core helium flash close to its peak by comparing the results of two and three-dimensional hydrodynamic simulations. We use a multidimensional Eulerian hydrodynamics code based on state-of-the-art…

Astrophysics · Physics 2015-05-13 M. Mocak , E. Mueller , A. Weiss , K. Kifonidis

Radiative mixing layers arise wherever multiphase gas, shear, and radiative cooling are present. Simulations show that in steady state, thermal advection from the hot phase balances radiative cooling. However, many features are puzzling.…

Astrophysics of Galaxies · Physics 2021-07-12 Brent Tan , S. Peng Oh , Max Gronke

Globally neutral neutron stars, obtained from the solution of the called Einstein-Maxwell-Thomas-Fermi equations that account for all the fundamental interactions, have been recently introduced. These configurations have a more general…

High Energy Astrophysical Phenomena · Physics 2015-06-23 S. M. de Carvalho , R. Negreiros , Jorge A. Rueda , Remo Ruffini

The amount and spatial pattern of heat extracted from cores of terrestrial planets is ultimately controlled by the thermal structure of the lower rocky mantle. Using the most common model to tackle this problem, a rapidly rotating and…

Earth and Planetary Astrophysics · Physics 2016-01-26 Wieland Dietrich , Kumiko Hori , Johannes Wicht

Lagrangian studies of the local temperature mixing and heat transport in turbulent Rayleigh-Benard convection are presented, based on three-dimensional direct numerical simulations. Contrary to vertical pair distances, the temporal growth…

Fluid Dynamics · Physics 2008-04-09 Joerg Schumacher

Semiconvection occurs in regions of stars and planets that are unstable to overturning convection according to the Schwarzschild criterion, yet stable according to the Ledoux criterion. Previous simulations in Cartesian boxes have advanced…

Solar and Stellar Astrophysics · Physics 2025-03-19 J. R. Fuentes

Three-dimensional (3D), time dependent numerical simulations, of flow of matter in stars, now have sufficient resolution to be fully turbulent. The late stages of the evolution of massive stars, leading up to core collapse to a neutron star…

Solar and Stellar Astrophysics · Physics 2014-01-30 W. David Arnett , Casey Meakin , Maxime Viallet