Here's a breakdown:
* Main Sequence Stars: These are the "normal" stars like our Sun, fusing hydrogen into helium in their cores.
* Red Giants: When a star runs out of hydrogen fuel, it expands and cools, becoming a red giant.
* Planetary Nebula: Some red giants expel their outer layers, creating a beautiful shell of gas known as a planetary nebula.
* White Dwarf: The hot, dense core of the red giant remains, now called a white dwarf. It is primarily composed of carbon and oxygen.
Important Notes:
* Stars larger than eight times the mass of our Sun end their lives in a spectacular supernova, leaving behind either a neutron star or a black hole.
* White dwarfs are incredibly dense – a teaspoonful of white dwarf material would weigh several tons on Earth!
* White dwarfs slowly cool over billions of years, eventually becoming black dwarfs. However, the universe is not old enough for any black dwarfs to exist yet.
