Internal Structure and Evolution of Very Massive Stars

Presupernova Evolution of Rotating Massive Stars I: Numerical Method and Evolution of the Internal Stellar Structure

The evolution of rotating stars with zero-age main sequence (ZAMS) masses in the range 8M⊙ to 25M⊙ is followed through all stages of stable evolution. The initial angular momentum is chosen such that the star’s equatorial rotational velocity on the ZAMS ranges from zero to ∼ 70% of break-up. The stars rotate rigidly on the ZAMS as a consequence of angular momentum redistribution during the pre-...

Evolution and Nucleosynthesis of Very Massive Primordial Stars

We investigate the evolution, final fate, and nucleosynthetic yields of rotating and non-rotating very massive stars (VMS) of zero metallicity. First we address the issue of mass loss during hydrogen burning due to vibrational instabilities. We find that these objects are much more stable than what was found in previous studies of VMS of solar composition, and expect only negligible mass loss d...

Evolution and Explosion of Very Massive Primordial Stars

While the modern stellar IMF shows a rapid decline with increasing mass, theoretical investigations suggest that very massive stars (& 100M⊙) may have been abundant in the early universe. Other calculations also indicate that, lacking metals, these same stars reach their late evolutionary stages without appreciable mass loss. After central helium burning, they encounter the electron-positron pa...

The evolution of rotating very massive stars with LMC composition⋆⋆⋆

Context. With growing evidence for the existence of very massive stars at subsolar metallicity, there is an increased need for corresponding stellar evolution models. Aims. We present a dense model grid with a tailored input chemical composition appropriate for the Large Magellanic Cloud (LMC). Methods. We use a one-dimensional hydrodynamic stellar evolution code, which accounts for rotation, t...

Evolution of Very Massive Stars with Pulsational Mass Loss