What mechanism characterizes a Type II supernova, often called a core-collapse supernova?
Exhaustion of nuclear fuel leading to core collapse and rebound.
Type II supernovae are the result of the natural, catastrophic death of a single star significantly more massive than the Sun after it has completely burned through all available nuclear fuel in its core. When fusion ceases, the immense outward thermal pressure that had previously counteracted gravitational forces vanishes instantly. Gravity takes over, causing the stellar core to collapse violently inward to densities approaching nuclear matter levels in less than a second. The outer stellar layers, which are still falling inward, collide with this newly compressed, incompressible core, creating a massive shockwave that blasts the exterior material outward in the visible Type II explosion.
