Life Cycle Of Stars Flashcards
What are the stages of the life cycle of stars
Cloud of dust and gas
Protostar
Main sequence star
Stars bigger than the sun go to red super giant then supernova then neutron star
Stars the same size as the sun go to red giant star then to white dwarf then to black dwarf
What do stars initially form from
From a cloud of dust and gas called a nebula and a force of gravity pulls the dust and gas together to from a protostar
What happens after it’s a protostar
The star will get denser and the temperature will rise so more particles will collide with each other
What happens when the protostar gets high enough
The hydrogen nuclei will undergo nuclear fusion to form a helium nuclei and this will give out huge amounts of energy keeping the core of the star hot and the main sequence star is born
What happens when the star in born into a main sequence star
Star enters a long stable period where the outward pressure caused by the nuclear fusion that tried to expand the star balances the force of gravity pulling everything inwards
How long will a star stay in it’s long stable period
Several billion years
When will the main sequence star come out of its long stable period
Once the hydrogen starts to run out
What will happen to a small star or a larger star when it starts to run out of hydrogen
The smaller star will swell into a red giant
The larger star will swell into a red super giant
Why do the stars become red
The surface of the star cools and fusion of helium occurs
Then heavier elements are created in the core of the star
What happens to the red giant
It will become unstable and eject its outer layer of dust and gas leaving behind a hot dense solid core called a white dwarf
What happens to the white dwarf
It will cool down and emit less and less energy
Once it no longer emits a significant amount of energy it’s called a black dwarf
What happens to the red super giant
As they undergo more fusion they start to glow brightly again and expand and counteract several times forming heavy elements in various nuclear reactions and eventually they’ll explode in a supernova
What happens when the star explodes in a supernova
It will form elements heavier than iron and eject then into the universe to form new planets and stars
What happens to the exploding supernova
It will throw out layers of dust and gas into space to leave a very dense core called the neutron star
If the original star was big enough it will become a black hole
What is a black hole
A super dense point in space that not even light can escape from
