Internal Structure of Very Massive Stars

Some models are computed for very massive stars (M=46.8M⊙) consisting of four regions: (I) a homogeneous radiative envelope, (II) a semiconvective intermediate zone, (III) a radiative intermediate zone and (IV) a homogeneous convective core. The semi-convective intermediate zone is formed in the consequence of growing convective instability which is characteristic in very massive stars and the distribution of composition in this region is determined so as to maintain the convective neutrality taking account of the effect of the gradient of mean molecular weight. It is shown that the very massive stars evolve essentially in the same way as less massive stars in their early phase and the growing convective instability has little influence on the effective temperature and luminosity of stars.