What remnant forms after a high-mass star exhausts core hydrogen and undergoes core collapse?
A neutron star or a black hole following a supernova.
When a high-mass star exhausts the hydrogen fuel in its core, its evolution path diverges sharply from that of lower-mass stars like the Sun. These stars rapidly contract, heat up, and initiate sequential fusion of heavier elements (helium, carbon, silicon) until an inert iron core forms. Iron fusion consumes energy rather than releasing it, leading to an immediate cessation of outward pressure. Gravity causes catastrophic collapse, which violently rebounds off the now incompressible core, resulting in a spectacular supernova explosion. The remnant left behind after this dramatic event is determined by the mass of the core that collapses: if the remnant mass is below a certain threshold, it stabilizes as an incredibly dense neutron star; if the mass is even greater, the collapse continues indefinitely, forming a black hole.
