Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· References in the article
· Citations to the Article (6) (Citation History)
· Refereed Citations to the Article
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
The STAROX stellar evolution code
Authors:
Roxburgh, Ian W.
Affiliation:
AA(Astronomy Unit, Queen Mary, University of London; LESIA, Observatoire de Paris)
Publication:
Astrophysics and Space Science, Volume 316, Issue 1-4, pp. 75-82 (Ap&SS Homepage)
Publication Date:
08/2008
Origin:
SPRINGER
Keywords:
Stars, Stellar evolution
DOI:
10.1007/s10509-007-9673-7
Bibliographic Code:
2008Ap&SS.316...75R

Abstract

This paper describes the STAROX stellar evolution code for the calculation of the evolution of a model of a spherical star. The code calculates a model at time t k , that is the run of pressure, density, temperature, radius, energy flux and related variables on a mesh in mass M i , given the distribution of chemical elements X j ( i) at t k and the model at the previous time step t k-1. It then advances the chemical composition to the next time step t k+1 and calculates a new model at time t k+1. This process is iterated to convergence. The model equations are solved by Newton Raphson relaxation; the chemical equations are solved by an iterative procedure, each element being advanced in turn, and the process repeated to convergence. Convection is modelled by a mixing length model and convective mixing is treated as a diffusive process; chemical overshooting can be incorporated in parametric form. The equation of state is taken from OPAL tables and the opacity from a blend of OPAL and Alexander tables. Nuclear reaction rates are from NACRE but only cover the p p chain and CNO cycle. The atmospheric layers are incorporated in the model by applying the surface boundary condition at small optical depth ( τ≈0.001). The mesh in mass M i is usually taken as fixed except that there is a moveable mesh point at the boundary of a convective core. Results are given for models of mass 0.9 and 5.0 M sun with initial composition X=0.7, Z=0.02 evolved to a state where the central hydrogen abundance is X c =0.35, and for a model of mass 2.0 M sun with initial X=0.72, Z=0.02, evolved to X c =0.01 and with core overshooting. In this latter case we compute two models one with and one without a moveable mesh point at the boundary of the convective core to illustrate the importance of having such a moveable mesh point for the determination of the Brunt Väisälä frequency in the layers outside the core.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints