White Dwarfs Observed Turning into Crystals
These ultra-dense remnants still emit thermal radiation as they cool, and are visible to astronomers as rather faint objects.
It is estimated that up to 97% of stars in our Milky Way Galaxy will eventually turn into white dwarfs, while the most massive of stars will end up as neutron stars or black holes.
The cooling of white dwarfs lasts billions of years. Once they reach a certain temperature, the originally hot matter inside the star’s core starts crystallizing, becoming solid.