Jesper Sollerman

Nyckelord: NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Supernova; Supernovae; Stripped-envelope supernovae; SN Type Ibc; SN; SNe; SN progenitor; Type Ibn; Astronomy; astronomi; Sammanfattning: Stripped-envelope supernovae were thought to be the explosions of very massive stars (& 20 M) that lost their outer layers of hydrogen and/or helium in strong stellar winds.

Abstract Stars are initially powered by the fusion of hydrogen to helium. These ashes serve as fuel in a series of stages1,2,3, transforming massive stars into a structure of shells. These are composed of natal hydrogen on the outside and consecutively heavier compositions inside, predicted to be dominated by He, C/O, O/Ne/Mg and O/Si/S (refs. 4,5). Silicon and sulfur are fused into iron, leading to the collapse of the core and either a supernova explosion or the formation of a black hole6,7,8,9.

Abstract Core-collapse supernovae are explosions of massive stars at the end of their evolution. They are responsible for metal production and for halting star formation, having a significant impact on galaxy evolution. The details of these processes depend on the nature of supernova progenitors, but it is unclear if Type Ic supernovae (without hydrogen or helium lines in their spectra) originate from core-collapses of very massive stars (>30 M⊙) or from less massive stars in binary systems.