8 Space Physics Flashcards
describe the lifecycle of a star
large star
nebula -> protostar -> main sequence star -> red super giant -> supernova
describe the lifecycle of a star 1st step
more detail
- form from a cloud of dust and gass called a nebula
describe the lifecycle of a star 2nd step
more detail
- force fo gravity pulls the dust and gass togeteher to form a protostar
- temp rises as the star gets denser and mor epaticles collide
- when temp high enough hydrogen nuceli undergo nuclear fusion to form helium nuceli
- gives out large amoutns of energy which keeps the core of the star hot
describe the lifecycle of a star 3rd step
more detail
the star enters a long stable period where the outward pressure caused by the nuclear fusion that trie to epand the star balances the force of gravity pulling everything inwards
during this stable period its called a main sequence star typically lasts several billion years
describe the lifecycle of a star 4th step
more detail
eventually hydrogen beging to run out
the star swells into a red giant/super red giant
becomes red because the surface cools down
fusion of helium qn other elements occurs
heavier elements up to iron are created in the core
describe the lifecycle of a star (red giant)
- small to medium sized stars become unstable and ejects its outer layer of dust and gas
- leaves a hot dense solid core - a white dwarf
- as a white dwarf cools down it emits less and less energy
- when it no longer emits a signifcant amouny itd is called a black dwarf
describe the lifecycle of a star (super red giant)
more detail
supernova:
- stars udnegro more fusion making them brighter and expand and contract several times forming heavy elements eg iron in various nuclear reactions
- eventually explode into supernovas ejecting elemnts into the universeto form new planets and stars
after supernova:
- throws the outer layers of dust and gas into space leaving a very dense core called a neutron star
- if the tar is large enougj it willl become a black hole
describe the lifecycle of a star
smaller star
nebula -> protostar -> main sequence star -> red giant -> white dwarf -> black dwarf
how much larger than the sun does a star have to be to become a red super giant
1.5
explain a nebula
A cloud of gas and
dust (mainly
hydrogen) where
new stars are born
explain a protostar
Gravity causes the dust nd gas in a nebula to become compact.
As the temperature increases a new star is
born.
explain a main-sequence star
The longest, most stable period of a star’s life where it converts hydrogen to helium in its core, generating heat and light.
explain a red super giant
After the hydrogen in a
giant star’s core has been
used up, they become the
largest stars in the universe.
Heavier elements are fused
(up to iron) and it expands
to a much larger size.
explain a red giant
For stars about the same size
as the sun. As the core runs
out of hydrogen and helium,
the outer layers of the star
expand, cool, and become a
dimmer red colour. Heavier
elements now start to form.
explain a supernova
A very heavy massive star
that collapses in on itself,
causing a violent explosion.
This produces an extremely
bright object that can last for
months. At these
temperatures the heaviest
elements form.
