Very large mass stars will eventually turn into what celestial object?

Very large mass stars, typically those with initial masses greater than about 20 times that of the Sun, undergo a series of nuclear fusion reactions in their cores. As these stars exhaust their nuclear fuel, they go through various stages of stellar evolution, culminating in a dramatic collapse. When the core's nuclear fuel is depleted, the outward pressure that supports the star against gravitational collapse diminishes. The core contracts and heats up until conditions are sufficient for the formation of a neutron star or, in the case of the most massive stars, a black hole.

For extremely massive stars, following the core collapse, their outer layers may be expelled in a massive explosion known as a supernova. This event can result in the formation of either a neutron star or a black hole, depending on the mass of the remnant core. If the core retains the necessary mass, it will ultimately collapse into a black hole, where the gravitational pull becomes so strong that nothing, not even light, can escape. This is why large mass stars can end their stellar life cycle as black holes rather than becoming other celestial objects.