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We describe an approach for finding the eigenfrequencies of solar acoustic modes (p modes) in a convective envelope in the WKB limit. This approximation restricts us to examining the effects of fluid motions which are large compared to the…

Astrophysics · Physics 2009-10-30 M. Swisdak , E. Zweibel

Asteroseismology involves using the resonant frequencies of a star to infer details about its internal structure and evolutionary state. Oscillation frequencies are most useful when accompanied by accurate measurements of the more…

Astrophysics · Physics 2007-05-23 Timothy R. Bedding

The asteroseismic modelling of period spacing patterns from gravito-inertial modes in stars with a convective core is a high-dimensional problem. We utilise the measured period spacing pattern of prograde dipole gravity modes (acquiring…

A qualitative study of the surface trapping of low-frequency non-radial g-modes in rotating early-type stars is undertaken within the Cowling, adiabatic and traditional approximations. It is demonstrated that, at frequencies below a…

Astrophysics · Physics 2009-10-31 R. H. D. Townsend

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the…

Solar and Stellar Astrophysics · Physics 2016-05-17 Joyce A. Guzik , T. H. Morgan , N. J. Nelson , C. Lovekin , K. Kosak , I. N. Kitiashvili , N. N. Mansour , A. Kosovichev

With the greater power to infer the state of stellar interiors provided by asteroseismology, it has become possible to study the survival of initially convective cores within stars during their main-sequence evolution. Standard theories of…

Solar and Stellar Astrophysics · Physics 2023-06-16 Mark Lykke Winther , Víctor Aguirre Børsen-Koch , Jakob Lysgaard Rørsted , Amalie Stokholm , Kuldeep Verma

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

Stellar convection plays an important role in atmospheric dynamics, wind formation and the mass-loss processes in Asymptotic Giant Branch (AGB) stars. However, a direct characterization of convective surface structures in terms of size,…

Gravitationally unstable disks can fragment and form bound objects provided that their cooling time is short. In protoplanetary disks radiative cooling is likely to be too slow to permit formation of planets by fragmentation within several…

Astrophysics · Physics 2011-02-11 Roman R. Rafikov

Axisymmetric magnetic activity on the Sun and Sun-like stars increases the frequencies of the modes of acoustic oscillation. However, it is unclear how a corotating patch of activity affects the oscillations, since such a perturbation is…

Solar and Stellar Astrophysics · Physics 2019-11-28 Emanuele Papini , Laurent Gizon

We summarize the current status of the turbulent model of star formation in turbulent molecular clouds. In this model, clouds, clumps and cores form a hierarchy of nested density fluctuations caused by the turbulence, and either collapse or…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

Convection is a fundamental physical process in the fluid cores of planets because it is the primary transport mechanism for heat and chemical species and the primary energy source for planetary magnetic fields. Key properties of…

Geophysics · Physics 2019-09-11 Céline Guervilly , Philippe Cardin , Nathanaël Schaeffer

Main-sequence massive stars possess convective cores that likely harbor strong dynamo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D anelastic spherical harmonic (ASH) code to…

Solar and Stellar Astrophysics · Physics 2015-05-20 Kyle C. Augustson , Allan S. Brun , Juri Toomre

Using linear non-adabatic pulsation analysis, we explore the radial-mode (p-mode) stability of stars across a wide range of mass (0.2 <= M <= 50 Msun), composition (0 <= X <= 0.7, Z=0.001, 0.02), effective temperature (3 000 <= T_eff <= 40…

Solar and Stellar Astrophysics · Physics 2016-03-09 C. S. Jeffery , H. Saio

The understanding of transport processes inside the stars is one of the main goals of asteroseismology. Chemical turbulent mixing can affect the internal distribution of \mu near the energy generating core, having an effect on the…

Astrophysics · Physics 2015-05-13 J. Montalban , A. Miglio , P. Eggenberger , A. Noels

Convection is ubiquitous in stellar and planetary interiors where it likely plays an integral role in the generation of magnetic fields. As the interiors of these objects remain hidden from direct observation, numerical models of convection…

Solar and Stellar Astrophysics · Physics 2026-01-22 Brandon J. Lazard , Nicholas A. Featherstone , Jonathan M. Aurnou

A set of long and nearly continuous observations of alpha Centauri A should allow us to derive an accurate set of asteroseismic constraints to compare to models, and make inferences on the internal structure of our closest stellar…

Solar and Stellar Astrophysics · Physics 2015-05-19 P. de Meulenaer , F. Carrier , A. Miglio , T. R. Bedding , T. L. Campante , P. Eggenberger , H. Kjeldsen , J. Montalban

We present photometric and spectroscopic analyses of gravity (g-mode) long-period pulsating hot subdwarf B (sdB) stars. We perform a detailed asteroseismic and spectroscopic analysis of five pulsating sdB stars observed with {\it TESS}…

1D stellar evolution calculations produce uncertain predictions for quantities like the age, core mass, core compactness, and nucleo-synthetic yields; a key source of uncertainty is the modeling of interfaces between regions that are…

[abridged] We investigate the velocity structure of protostellar cores that result from non-magnetic numerical models of the gravoturbulent fragmentation of molecular cloud material. A large fraction of the cores analyzed are ``quiescent'',…