Development of a Computer Code for the Calculation of Stellar Evolution, with Applications to Solar Models of Low Neutrino Flux.
A general purpose computer code was developed to allow the detailed calculation of evolutionary sequences of hydrostatic stellar models under many circumstances of astrophysical interest. Solution of the structure equations is by the relaxation technique throughout the star, without explicit integration and fitting for the outer envelope. A matrix method of algebraic solution of the finite difference equations is employed, together with a modification of that method for the treatment of the central boundary condition. It is demonstrated how the matrix technique allows determination of the derivatives of the matching condition in a single integration. The modification of the code for the purpose of detailed evolutionary calculation of a portion of a star is presented, through the modification of the boundary conditions to represent in simple fashion the remainder of the star. Stability and convergence problems encountered in earlier versions of the code are discussed, as well as the techniques used to overcome them.
- Pub Date:
- Physics: Astronomy and Astrophysics;
- Computer Programs;
- Flux (Rate);
- Stellar Evolution;
- Finite Difference Theory;
- Matrices (Mathematics);