SN1987A - EVOLUTION OF THE TEMPERATURE AND IONIZED FRACTION OF THE EXPANDING ENVELOPE

The evolution of the temperature and ionization fraction of the expand ing envelope of SN1978A are discussed by use of the recombination theo ry of hydrogen. Temperature and ionization fraction are two fundamenta l parameters in the studies of supernova, but they are hard to be dete rmined by the traditional methods. A new approach to their evolutions is proposed based on the fact that the evolutional information of thes e two parameters must be contained in line variation because the chang es in them govern the line variation behavior. The two parameters depe nd on each other, so they should be calculated simultaneously. By comp aring the theoretical Ha light curve deduced from the radiative transf er theory using the escaping probability approximation with the observ ational, the evolutions of them are achieved.