White dwarfs are the remnants of dead stars after they have used up all their fuel. They are incredibly dense and typically have a mass similar to our Sun’s but in a more compact size. Despite that, white dwarfs can emit a significant amount of light and heat, and scientists study them to understand better the processes that govern the universe.

But don’t worry—our Sun won’t become a white dwarf for about 6 billion years. Plenty of time left.