scholarly journals Testing theoretical stellar interior and HED plasma opacities at the Sandia Z

2019 ◽  
Author(s):  
Anil K. Pradhan
Keyword(s):  
Stellar Interior

Probing solar and stellar interior dynamics and dynamo

2008 ◽  
Vol 41 (6) ◽  
pp. 830-837 ◽  
Author(s):  
Alexander G. Kosovichev
Keyword(s):  
Stellar Interior

Experimental investigation of opacity models for stellar interior, inertial fusion, and high energy density plasmas

2009 ◽  
Vol 16 (5) ◽  
pp. 058101 ◽  
Author(s):  
J. E. Bailey ◽  
G. A. Rochau ◽  
R. C. Mancini ◽  
C. A. Iglesias ◽  
J. J. MacFarlane ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Inertial Fusion ◽  
Stellar Interior ◽  
High Energy Density Plasmas

scholarly journals Theoretical Predictions of Surface Light Element Abundances in Protostellar and Pre-Main Sequence Phase

2021 ◽  
Vol 8 ◽  
Author(s):  
E. Tognelli ◽  
S. Degl’Innocenti ◽  
P. G. Prada Moroni ◽  
L. Lamia ◽  
R. G. Pizzone ◽  
...  
Keyword(s):  
Cross Sections ◽  
Main Sequence ◽  
Light Element ◽  
Element Abundance ◽  
Light Elements ◽  
Convective Envelope ◽  
Stellar Envelope ◽  
Element Abundances ◽  
Stellar Interior ◽  
Theoretical Predictions

Theoretical prediction of surface stellar abundances of light elements–lithium, beryllium, and boron–represents one of the most interesting open problems in astrophysics. As well known, several measurements of 7Li abundances in stellar atmospheres point out a disagreement between predictions and observations in different stellar evolutionary phases, rising doubts about the capability of present stellar models to precisely reproduce stellar envelope characteristics. The problem takes different aspects in the various evolutionary phases; the present analysis is restricted to protostellar and pre-Main Sequence phases. Light elements are burned at relatively low temperatures (T from ≈2 to ≈5 million degrees) and thus in the early evolutionary stages of a star they are gradually destroyed at different depths of stellar interior mainly by (p, α) burning reactions, in dependence on the stellar mass. Their surface abundances are strongly influenced by the nuclear cross sections, as well as by the extension toward the stellar interior of the convective envelope and by the temperature at its bottom, which depend on the characteristics of the star (mass and chemical composition) as well as on the energy transport in the convective stellar envelope. In recent years, a great effort has been made to improve the precision of light element burning cross sections. However, theoretical predictions surface light element abundance are challenging because they are also influenced by the uncertainties in the input physics adopted in the calculations as well as the efficiency of several standard and non-standard physical processes active in young stars (i.e. diffusion, radiative levitation, magnetic fields, rotation). Moreover, it is still not completely clear how much the previous protostellar evolution affects the pre-Main Sequence characteristics and thus the light element depletion. This paper presents the state-of-the-art of theoretical predictions for protostars and pre-Main Sequence stars and their light element surface abundances, discussing the role of (p, α) nuclear reaction rates and other input physics on the stellar evolution and on the temporal evolution of the predicted surface abundances.

Convective Overshooting in Stellar Interior Models

1973 ◽  
Vol 184 ◽  
pp. 191 ◽  
Author(s):  
Giora Shaviv ◽  
Edwin E. Salpeter
Keyword(s):  
Stellar Interior

On equation of state interpolation errors in stellar interior calculations

1991 ◽  
Vol 381 ◽  
pp. 228 ◽  
Author(s):  
Ben Dorman ◽  
Alan W. Irwin ◽  
Brian B. Pedersen
Keyword(s):  
Equation Of State ◽  
Stellar Interior

scholarly journals On Magnetic Mixing and Rotation in Stellar Evolution

1978 ◽  
Vol 80 ◽  
pp. 323-331
Author(s):  
Peter G. Gross
Keyword(s):  
Magnetic Fields ◽  
Stellar Evolution ◽  
Evolutionary Status ◽  
Relevant Parameter ◽  
Stellar Rotation ◽  
Convective Turbulence ◽  
Stellar Interior ◽  
Magnetic Mixing ◽  
Ap Stars

In this paper some thoughts and problems are presented from the viewpoint that the evolution of stars may play a key role in generating magnetic fields which, in turn, may affect the mixing of nuclearly processed elements from the stellar interior to the surface. The relevant parameter is stellar rotation which, upon interaction with convective turbulence driven by thermal instabilities, leads to the generation of magnetic fields. A possible connection to Bidelman's hypothesis on the evolutionary status of Ap stars is also discussed in the context of a post-core-helium-flash hypothesis.

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