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Related papers: Calibrating Core Overshooting Parameters With Two-…

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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

Convective cores are the hydrogen reservoirs of main sequence stars that are more massive than around 1.2 solar masses. The characteristics of the cores have a strong impact on the evolution and structure of the star. However, such results…

Solar and Stellar Astrophysics · Physics 2023-08-09 Anthony Noll , Sébastien Deheuvels

By direct hydrodynamic simulation, using the Piecewise Parabolic Method (PPM) code PROMETHEUS, we study the properties of a convective oxygen burning shell in a SN 1987A progenitor star prior to collapse. The convection is too heterogeneous…

Astrophysics · Physics 2009-10-30 Grant Bazán , David Arnett

We discuss the effects of convective overshooting in the PMS evolution of intermediate mass stars, by analysing in detail the early evolution towards the main sequence of a 2 M_sun stellar model. These effects can be extremely important in…

Astrophysics · Physics 2009-11-11 J. P. Marques , M. J. P. F. G. Monteiro , J. Fernandes

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

The size of convective cores remains uncertain, despite its substantial influence on stellar evolution, and thus on stellar ages. The seismic modeling of young subgiants can be used to obtain indirect constraints on the core structure…

Solar and Stellar Astrophysics · Physics 2021-04-30 A. Noll , S. Deheuvels , J. Ballot

1D and 2D supernova simulations for stars between 11 and 25 solar masses are presented, making use of the Prometheus/Vertex neutrino-hydrodynamics code, which employs a full spectral treatment of the neutrino transport. Multi-dimensional…

Astrophysics · Physics 2009-11-11 R. Buras , H. -Th. Janka , M. Rampp , K. Kifonidis

The physical parameters of the retired A star HD 185351 were analysed in great detail by Johnson et al. (2014) using interferometry, spectroscopy and asteroseismology. Results from all independent methods are consistent with HD 185351…

We perform the first multidimensional fluid simulations of thermonuclear helium ignition underneath a hydrogen-rich shell. This situation is relevant to Type I X-ray bursts on neutron stars that accrete from a hydrogen-rich companion. Using…

High Energy Astrophysical Phenomena · Physics 2024-11-21 Simon Guichandut , Michael Zingale , Andrew Cumming

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

In spite of the great effort made in the last decades to improve our understanding of stellar evolution, significant uncertainties remain due to our poor knowledge of some complex physical processes that require an empirical calibration,…

Solar and Stellar Astrophysics · Physics 2015-06-22 Alessandro Bressan , Leo Girardi , Paola Marigo , Philip Rosenfield , Jing Tang

We present a comprehensive set of stellar evolution models for Procyon A in an effort to guide future measurements of both traditional stellar parameters and seismic frequencies towards constraining the amount of core overshoot in Procyon A…

Astrophysics · Physics 2009-11-11 Christian W. Straka , Pierre Demarque , D. B. Guenther

Radiation-hydrodynamical simulations of surface convection in low-mass stars can be exploited to derive estimates of i) the efficiency of the convective energy transport in the stellar surface layers; ii) the convection-related photometric…

Astrophysics · Physics 2009-11-13 Hans-G. Ludwig , Elisabetta Caffau , Arunas Kucinskas

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

A binary liquid near its consolute point exhibits critical fluctuations of the local composition; the diverging correlation length has always challenged simulations. The method of choice for the calculation of critical points in the phase…

Statistical Mechanics · Physics 2021-04-29 Yogyata Pathania , Dipanjan Chakraborty , Felix Höfling

The classical 'ballistic' overshoot models show some contradictions and are not consistence with numerical simulations and asteroseismic studies. Asteroseismic studies imply that overshoot is a weak mixing process. Diffusion model is…

Solar and Stellar Astrophysics · Physics 2016-03-09 Q. S. Zhang

We evaluated the bias and variability on the fitted age and convective core overshooting parameter for evolved binary stars accounting for observational and internal uncertainties. We considered a binary system composed of a 2.50 $M_{\sun}$…

Solar and Stellar Astrophysics · Physics 2018-07-18 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti

A proposed setting for thermonuclear (Type Ia) supernovae is a white dwarf that has gained mass from a companion to the point of carbon ignition in the core. In the early stages of carbon burning, called the simmering phase, energy released…

Solar and Stellar Astrophysics · Physics 2025-01-29 Brendan Boyd , Alan Calder , Dean Townsley , Michael Zingale

A calibration of the mixing-length parameter in the local mixing-length theory (MLT) is presented for the lower part of the convection zone in pure-hydrogen atmosphere white dwarfs. The parameterization is performed from a comparison of 3D…

Solar and Stellar Astrophysics · Physics 2015-06-23 P. -E. Tremblay , H. -G. Ludwig , B. Freytag , G. Fontaine , M. Steffen , P. Brassard

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
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