Stellar evolution. i. a program for the solution of the time-dependent basic equations <sternentwicklung. i. ein program zur losung der zeitabhingigen aufbaugleichungen<

Abstract

In this paper a program is described for stellar evolution computations, based on the Henyey method. The program shall be used for very different phases of stellar evolution. Therefore, the main program for the solution of the time dependent basic equations is kept as general as possible, while all assumptions about special physical conditions in the star occur only in subprograms. Hence the range of applicability of the program can easily be extended. The system of difference equations and details of the integration method used in the program are given in two appendices. For a first test the program has been applied to the post-main sequence evolution of a star of 7 M; the results will appear in part II and III. Some technical details of these calculations are given and discussed here. The program turned out to be applicable to calculations of the evolution near the main sequence, of phases of core contraction and of nuclear burning in shell sources.