What does a white dwarf eventually become as it cools?

A white dwarf is the remnant core of a star that has exhausted its nuclear fuel and shed its outer layers. As it cools over time, it becomes less luminous and its temperature decreases. Theoretical models predict that after billions of years, when a white dwarf has fully cooled and no longer emits significant energy, it will transition into a black dwarf. This stage is characterized by a star that is no longer radiating heat or light; it has effectively reached a state of thermal equilibrium with its surroundings.

In contrast, the other options represent different stages of stellar evolution or types of astronomical objects. A supernova occurs when massive stars explode at the end of their life cycle, while a neutron star is formed when a more massive star collapses under its gravity after a supernova event. A red giant is an earlier phase in stellar evolution, occurring when a star expands and cools after exhausting hydrogen in its core. These processes do not relate directly to what happens to a white dwarf as it progresses toward its final outcomes.