Answer:
Nasa said :
Step-by-step explanation:
Step 1 - Green - A cloud of gas and dust collapses due to gravity, creating a protostar.
Step 2 - Blue - Gravitational energy powers the young star until...
Step 3 - Yellow - …nuclear fusion occurs. The main sequence star may live millions or even
billions of years.
Step 4 - Red - The star expands into a red giant when the star's hydrogen level drops.
Step 5 - Orange - Different fusion processes occur. The star expands, cools, and loses mass
each time.
Step 6 - White - Fusion stops and a supernova explosion occurs. Most of the star is blown
away.
Step 7 - Black - Depending on the original star’s mass, either a black hole or neutron star
remains.
Step 8 - Green - The material shed during the star's life joins new gas clouds, and new stars
are formed.