Life Cycle Of A Star Flashcards
Formation of a star
Same mass as ours
Nebula - cloud of dust and gas
Protostar- force of gravity pulls these pieces together
Main sequence-Fusion of hydrogen nuclei to helium nuclei keeps the suns temperature stable
Red giant-Hydrogen runs out and the outward pressure from the core is more powerful than the inward pressure causing the sun to expand
White dwarf- Red giant becomes unstable and ejects all layers leaving the core behind
Black dwarf-Occurs when the white dwarf cools
Formation of a star
Larger than our own
Planetary nebula - A cloud of dust and gas.
Protostar-Gravity pulls the gas and dust together.
Main sequence- The star is kept stable via hydrogen fusion.
Red SUPER giant - expands when hydrogen runs out however fusion of other elements such as iron occurs .
Supernova -fusion of elements up to iron occurs , eventually an explosion will happen causing forming elements heavier than iron .
Neutron star / Black hole - depending on the mass of the star either an extremely dense core is left called a neutron star or a super dense point in which light cannot escape is formed called a black hole.
Why are planets constantly acclerating
It is moving in a circular orbit therefore it it constantly changing direction .
It is also changing velocity . NOT SPEED.
What is red shift
When we look at light from most distant galaxies the wavelength has increased . They are all longer than they should be . They are shifting to the red end of the spectrum.
Red shift is evidence that the universe is constantly expanding
At what stage in a suns life cycle is elements heavier than iron formed ?
When a supernova occurs elements heavier than iron occur in several nuclear reactions .
