The Life Cycle of a Starby Haylee



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The life cycle of a star can be compared to that of a human!



Protostars

Stars are born in a nebula--a cloud of hydrogen and helium gas and dust in space.Gravity causes the dust and gas to combine and atoms are added to the protostar.Nuclear fusion then turns hydrogen into helium, and the star is born.

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Main Sequence
A star is in it's main sequence for most of it's life. About fifty million years.This is when hydrogen is continuously fusing into helium and there is a battle going on to create equilibrium within the star.This is a battle between gravity and gas pressure.Over billions of years, the star slowly contracts as the temperature, density, and pressure increase.


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After Main Sequence
The "deaths" of stars can vary based on the mass.A lower mass star, much like our own sun, puffs its outer layer to produce expanding planetary nebulae. This is where new stars can form.A star with a large mass can explode into a supernova. It may also form a neutron star or a black hole!Big stars can become red supergiants! This happens when the star is finished fusing all the hydrogen.The core of the star becomes hotter and denser. And will later become a white dwarf.

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A star becomes a black hole win gravity wins the battle.





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Supernova!

Red Dwarfs
These are small stars, even smaller than our sun, and are very cool. They last a long time. Almost 100 billion years.


White Dwarf
When a star is in this stage of life, it is nearing the end. These are very small and very hot masses. Later they cool and fade after many years.


Blue Giants



For more Information












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This website has good information -----> Life Cycle of a Star