Here's why:
* White dwarfs are the remnants of stars like our Sun. After a star exhausts its nuclear fuel, it sheds its outer layers, leaving behind a dense, hot core.
* This core is incredibly dense, packed with electrons. It's about the size of the Earth, but can have the mass of our Sun.
* The white dwarf slowly radiates away its remaining heat. This process can take billions of years, during which time the white dwarf gradually cools and dims, eventually becoming a black dwarf (though this process is so slow that no black dwarfs are thought to exist yet).
Let me know if you'd like to know more about white dwarfs or other stellar remnants!
