Mass-loss predictions for evolved very metal-poor massive stars

Pre-supernova mass loss predictions for massive stars

Massive stars and supernovae (SNe) have a huge impact on their environment. Despite their importance, a comprehensive knowledge of which massive stars produce which SNe is hitherto lacking. We use a Monte Carlo method to predict the mass-loss rates of massive stars in the Hertzsprung-Russell Diagram (HRD) covering all phases from the OB main sequence, the unstable Luminous Blue Variable (LBV) s...

Evolution of Very Massive Stars with Pulsational Mass Loss

Mass loss predictions for hot stars

I present the results of radiation-driven mass-loss predictions for hot stars of all mass. Mass loss is an important aspect for the evolution of massive stars, the rotational properties of the progenitors of gamma-ray bursts, and is essential in assessing whether the most massive stars explode as pair-instability supernovae, or avoid them due to mass loss. As a result, the rate of mass loss is ...

Mass loss predictions for Subdwarf B stars

We present the results of Monte Carlo mass-loss computations for hot low-mass stars, specifically for Subdwarf B (SdB) stars. It is shown that the massloss rates on the Horizontal Branch (HB) computed from radiative line-driven wind models are not high enough to create SdB stars. We argue, however, that mass loss plays a role in the chemical abundance patterns observed both in field SdB stars, ...

Sulphur abundance in very metal-poor stars

We have obtained high-resolution high signal-to-noise spectra of the S i nearinfrared doublet at 8694 Å in eight metal-poor stars with metallicities in the range −0.6 ≤[Fe/H]≤ −3.0. Elemental sulphur abundances were derived for six targets and upper limits were set for two of the most metal-poor stars in the sample. The sulphur doublet at 8694.62 Å has been detected in three stars (HD19445, HD2...