The equations of stellar structure: mass conservation and hydrostatic equilibrium

2015 ◽  
Author(s):  
James MacDonald
Keyword(s):  
Mass Conservation ◽  
Hydrostatic Equilibrium ◽  
Stellar Structure

scholarly journals A Model for Adiabatic Mass-loss

2008 ◽  
Vol 4 (S252) ◽  
pp. 419-420
Author(s):  
Hongwei. Ge ◽  
R. F. Webbink ◽  
Z. Han
Keyword(s):  
Heat Flow ◽  
Mass Loss ◽  
Hydrostatic Equilibrium ◽  
Stellar Structure ◽  
Close Binary ◽  
Common Envelope ◽  
Compute Model ◽  
Binary Evolution ◽  
Structure Code

AbstractWe describe our work on the development and application of a stellar structure code to compute model sequences representing donor stars in interacting binaries subject to rapid (adiabatic) mass-loss. The donor star is assumed to remain in hydrostatic equilibrium, but no heat flow is allowed. These sequences can be used to define bifurcation sequences in close binary evolution, and to circumscribe possible survivors of common envelope evolution.

scholarly journals Hydrostatic equilibrium and stellar structure inf(R)gravity

2011 ◽  
Vol 83 (6) ◽  
Author(s):  
S. Capozziello ◽  
M. De Laurentis ◽  
S. D. Odintsov ◽  
A. Stabile
Keyword(s):  
Hydrostatic Equilibrium ◽  
Stellar Structure

EQUATION OF STELLAR STRUCTURE IN HAYASHI’S NEW GENERAL RELATIVITY

1995 ◽  
Vol 10 (15) ◽  
pp. 2225-2230 ◽  
Author(s):  
C.M. ZHANG ◽  
P.D. ZHAO
Keyword(s):  
General Relativity ◽  
Coordinate System ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Hydrostatic Equilibrium ◽  
Stellar Structure ◽  
Gravitation Theory ◽  
Tetrad Field

The general form of the parallelism tetrad field in the Schwarzschild coordinate system is presented in the framework of Hayashi’s gravitation theory with torsion. In the case of the symmetric energy-momentum tensor, we obtain the approximated equation of stellar structure, which, as a limit, is the Oppenheimer-Volkoff equation for hydrostatic equilibrium in general relativity.

scholarly journals Invariant quantities of scalar–tensor theories for stellar structure

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Aleksander Kozak ◽  
Aneta Wojnar
Keyword(s):  
Wide Class ◽  
Hydrostatic Equilibrium ◽  
Stellar Structure ◽  
Tensor Representation ◽  
Equilibrium Equations ◽  
Tensor Invariants ◽  
Physical Role ◽  
Gravitational Theories ◽  
Structure Equations

AbstractWe present the relativistic hydrostatic equilibrium equations for a wide class of gravitational theories possessing a scalar–tensor representation. It turns out that the stellar structure equations can be written with respect to the scalar–tensor invariants, allowing to interpret their physical role.

scholarly journals A Dialogue on Dynamical Pre-Main Sequence Tracks

2001 ◽  
Vol 200 ◽  
pp. 492-495 ◽  
Author(s):  
Günther Wuchterl
Keyword(s):  
Main Sequence ◽  
Thermal Structure ◽  
Brown Dwarfs ◽  
Young Star ◽  
Hydrostatic Equilibrium ◽  
Young Stars ◽  
Stellar Atmospheres ◽  
Stellar Structure ◽  
Sequence Evolution ◽  
Stellar Matter

Based on the theory of stellar structure and evolution combined with the theory of stellar atmospheres theoretical properties of young stars can be calculated. These calculations of pre-main sequence evolution have been refined over the last decades and do now provide theoretical spectra and colours even for very cool objects like young stars brown dwarfs and planets. Two of their key assumptions must become invalid towards the formation phases: (1) the hydrostatic equilibrium of pressure forces and gravity that assumes stellar matter to be at rest and (2) the non-dependence on the initial thermal structure. The former (1) is violated by accretion- and collapse flows, the latter (2) because a new born young star is observed with the specific thermal structure produced by the cloud collapse. I discuss changes in the theoretical properties of young stars that follow from calculating the pre-main sequence evolution as the consequence of the collapse of Bonnor-Ebert spheres.

scholarly journals A Seismic Model of the Solar Convective Envelope

1998 ◽  
Vol 185 ◽  
pp. 81-84
Author(s):  
H. Shibahashi ◽  
K.M. Hiremath ◽  
M. Takata
Keyword(s):  
Equation Of State ◽  
Sound Speed ◽  
Mass Conservation ◽  
Hydrostatic Equilibrium ◽  
Helium Abundance ◽  
Speed Profile ◽  
Seismic Model ◽  
Convective Envelope ◽  
Sound Speed Profile ◽  
Basic Equations

We determine the structure of the solar convective envelope by solving the basic equations for mass conservation and hydrostatic equilibrium with the imposition of the sound-speed profile determined from helioseismology and the equation of state. The solution is required to match with the structure of the radiative core, which is also determined with the imposition of the sound speed profile. The helium abundance is obtained as a part of the solutions.

scholarly journals Stellar Structure in a Newtonian Theory with Variable G

Physics ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1123-1132
Author(s):  
Júlio C. Fabris ◽  
Túlio Ottoni ◽  
Júnior D. Toniato ◽  
Hermano Velten
Keyword(s):  
Spatial Dependence ◽  
Equilibrium Structure ◽  
Hydrostatic Equilibrium ◽  
Stellar Structure ◽  
Polytropic Index ◽  
Gravitational Coupling ◽  
Matter Distribution ◽  
Newtonian Theory ◽  
Emden Equation ◽  
Variable G

A Newtonian-like theory inspired by the Brans–Dicke gravitational Lagrangian has been recently proposed by us. For static configurations, the gravitational coupling acquires an intrinsic spatial dependence within the matter distribution. Therefore, the interior of astrophysical configurations may provide a testable environment for this approach as long as no screening mechanism is evoked. In this work, we focus on the stellar hydrostatic equilibrium structure in such a varying Newtonian gravitational coupling G scenario. A modified Lane–Emden equation is presented and its solutions for various values of the polytropic index are discussed. The role played by the theory parameter ω, the analogue of the Brans–Dicke parameter, in the physical properties of stars is discussed.

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