Life Cycle Of Stars Flashcards
How does a star form?
Stars are formed from clouds of gas, hydrogen, helium and dust.
2nd step
Protostars form when gravity collects this cloud together and as it is
compressed it heats up.
3rd step
In main sequence stars, hydrogen fuses to form helium. This creates enough radiation and gas pressure to balance the gravitational forces.
4th step for the larger mass star
The hydrogen fuel begins to run out and the star will begin to fuse helium into larger
elements (e.g. iron). This increases the gas and radiation pressure. The star will expand and become a
Supergiant.
5th step for the larger mass star
The helium fuel begins to run out and the reaction will slow. The star becomes very unstable and will explode in a supernova, throwing gases and dust out into space. The high pressure and temperature in a supernova will cause the fusion of the heaviest elements.
Final step for the larger mass star
The remaining matter will collapse due to the gravitational force as the gas and radiation pressure will be small and shrink to form a
Neutron star or a Black hole.
4th step for the low mass star
The hydrogen fuel begins to run out and the star will begin to fuse helium into larger elements (e.g. carbon). This increases the gas and radiation pressure. The star will expand and become a Red
giant.
Last step for the low mass star
The helium fuel begins to run out and the reaction will slow. The gas and radiation
pressure will decrease. The star will shrink and
become a White dwarf.
