Sung-Chul Yoon

Low-metallicity massive single stars with rotation. Evolutionary models applicable to I Zwicky 18

Massive rotating single stars with an initial metal composition appropriate for the dwarf galaxy I Zw 18 ([Fe/H]=

Single Rotating Stars and the Formation of Bipolar Planetary Nebula

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Evolution towards and beyond accretion-induced collapse of massive white dwarfs and formation of millisecond pulsars

1.7) are modelled during hydrogen burning for initial masses of 9-300 M

Explosion and nucleosynthesis of low-redshift pair-instability supernovae

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Phosphorus in the young supernova remnant Cassiopeia A.

and rotational velocities of 0-900 km s

Type Ib and IIb Supernova Progenitors in Interacting Binary Systems

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Inferring supernova IIb/Ib/Ic ejecta properties from light curves and spectra: correlations from radiative-transfer models

. Internal mixing processes in these models were calibrated based on an observed sample of OB-type stars in the Magellanic Clouds. Even moderately fast rotators, which may be abundant at this metallicity, are found to undergo efficient mixing induced by rotation resulting in quasi chemically-homogeneous evolution. These homogeneously-evolving models reach effective temperatures of up to 90 kK during core hydrogen burning. This, together with their moderate mass-loss rates, make them Transparent Wind Ultraviolet INtense stars (TWUIN star), and their expected numbers might explain the observed HeII ionizing photon flux in I Zw 18 and other low-metallicity HeII galaxies. Our slowly rotating stars above

Rotating Stars and the Formation of Bipolar Planetary Nebulae II: Tidal Spin-up

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UKIRT Widefield Infrared Survey for Fe

80 M

OPTICAL MULTI-CHANNEL INTENSITY INTERFEROMETRY - OR: HOW TO RESOLVE O-STARS IN THE MAGELLANIC CLOUDS

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