•The inner part of the core is compressed into neutrons (c), causing
infalling material to bounce (d)and form an outward-propagating shock
front (red). The shock starts to stall (stand ( (e), but it is re-invigorated (تنشّط) by a
process that may include neutrino interaction. The surrounding material is blasted away (f), leaving only a
degenerate remnant.
•Within a massive, evolved star (a) the
onion-layered shells of elements undergo fusion, forming an iron core (b) that
reaches Chandrasekhar-mass and starts to collapse.