What process triggers the catastrophic collapse leading to a Type II supernova?
Answer
Fusing iron in the core consumes energy
When a massive star develops an inert core of iron, fusing iron consumes energy instead of releasing it, causing the core to collapse catastrophically in seconds.

Related Questions
What state does a low-mass star, like our Sun, eventually settle into after exhausting its core hydrogen?What is the general minimum initial mass threshold required for a star to become a Type II supernova progenitor?What process triggers the catastrophic collapse leading to a Type II supernova?What is required for a white dwarf remnant to cause a Type Ia supernova explosion?What quantum mechanical effect primarily supports a white dwarf against gravitational collapse?What remnant is typically left after a Type II (core-collapse) supernova?Why can a star with a mass similar to the Sun not become a Type II supernova progenitor?Approximately what mass does a white dwarf approach in a binary system to trigger a Type Ia supernova?What fundamental difference distinguishes the initiating force of a Type Ia event from a Type II event?What is the eventual fate of the Sun?What pressure momentarily halts the collapse after the iron core implosion in a massive star, leading to a Type II explosion?