life Cycle of a larGe
Mass staR
The Mysterious Universe
Ryan Barrie
Life Cycle of a large star
If a star is above 1.4 solar masses, the star is classified as a "large" star and has a similar path of stages to the small star until the main sequence stage (see stages 1-3), until the hydrogen has fused into helium, although this may take may take billions of years in a smaller mass star it takes only millions to evolve to this stage.
Stage 1: Red supergiant (after main sequence)although some supergiants can reach up to 1500 times the size of the sun they are less dense due to the shell of cooling and expanding gas that surrounds the dense helium core. (The star must reach 5 times greater or more to be a red giant).
Core temperatures increase, which eventually causes more fusion processes, forming nitrogen, oxygen and iron eventually. |
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Stage 2:
Over the next million years, nuclear reactions form creating many elements around the core.
Stage 3: Supernova
Once the core becomes purely iron, there is no more stable element to fuse into (that requires a release of energy) so in less than a second the Star enters the final stage and has a gravitational collapse, the core temperature rises to upwards of 100 billion degrease and causes a supernova explosion.