(Received August 19, 1959)
The internal structure of very masive stars with 46.8 solar masses is investigated in their early stage of evolution. Starting from an initial homogeneous model, their evolution is followed to the stage where the hydrogen in the core diminished to nine per cent in weight. The inhomogeneous models consist of three regions, a hydrogen-rich envelope, a hydrogen-consuming core, and a semi-convective intermediate zone. In the last zone, the mean molecular weight varies continuously and its distribution is determined by the condition of convective neutrality, where the gradient of mean molecular weight resulting from the convective mixing between the envelope and the core is taken into account. It is shown that the stars stay in the H-R diagram nearly at the same position as the main sequence stars until the hydrogen in the core is mostly exhausted and their life is about 3 × 106 years.
URL : http://ptp.ipap.jp/link?PTP/22/830/
DOI : 10.1143/PTP.22.830