Here's why:
* High-mass stars (over 8 solar masses) have enough gravity to fuse heavier elements in their cores, eventually becoming supernovae and leaving behind either neutron stars or black holes. They don't form white dwarfs.
* Low-mass stars (like our Sun) lack the necessary mass to fuse heavier elements. They eventually shed their outer layers as planetary nebulae, leaving behind their hot, dense cores as white dwarfs.
Key points about white dwarfs:
* They are incredibly dense, packing the mass of our Sun into a volume roughly the size of Earth.
* They are primarily composed of carbon and oxygen, the remnants of stellar fusion.
* They cool down very slowly over billions of years, eventually becoming black dwarfs (a theoretical stage, as the universe is not old enough for any black dwarfs to exist yet).
Let me know if you have any other questions!
