What are small, dense remnants of low-mass stars known as?

Small, dense remnants of low-mass stars are known as white dwarfs. When a low-mass star (like those similar to our Sun) exhausts its nuclear fuel, it enters the latter stages of its life cycle, shedding its outer layers and leaving behind a hot, dense core. This core is what we refer to as a white dwarf.

White dwarfs are typically composed mainly of carbon and oxygen, formed from the fusion processes that occurred during the star's lifetime. They are incredibly dense, packing a significant amount of mass into a volume comparable to that of Earth. Over time, white dwarfs will cool and fade, but they do not undergo further fusion reactions.

In contrast, red giants represent a stage in a star’s life cycle where it expands and cools after exhausting hydrogen in its core; neutron stars are remnants of high-mass stars and result from supernova explosions; black holes exist when a massive star collapses under its own gravity after going through a supernova. Thus, white dwarfs specifically define the remnants of low-mass stars.