On the Explosion of Type II Supernova

Various nuclear reactions which would take place after the collapse of stellar core caused by Fe →He reaction at the iron core of aged massive stars are investigated and it is shown that an enormous amount of energy from rapid nuclear reactions among light elements such as oxygen and carbon gives rise to the generation of shock wave. The rate of energy generation and the total amount of energy released are calculated, assuming a sort of burning front advancing outwards in the star, to be about 1047 erg/sec and 1051 ∼1052 erg, respectively. The behavior of propagation of the shock wave is calculated by the use of the method of Ôno et al. with a model of giant stars with mass of 15.6 M⊙ presented by Hayashi et al. Escape of radiation from the shock front is also considered when the shock approaches the stellar surface. Then it is shown that the maximum luminosity is about 3 ×1043 erg/sec, the maximum temperature about 105°K, the width of peak of light curve at the maximum luminosity 105 ∼6 sec and the expanding velocity of matter (0.5 ∼1) ×108 cm/sec. The fact that these values are fairly consistent with the observational data of Type II supernova appears to show that the massive stars may possibly become Type II supernovae at the last phase of giant stage.