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14 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Life cycle of a star |
Nebula • protostar • main sequence star • red giant (1.4 x sun or smaller) • white dwarf • black dwarf |
OR Nebula • protostar • main sequence star • red super giant • supernovae • neutron star of black hole |
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Nebulla |
Cloud of dust and gas Force of gravity pulls it together to form a protostar |
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Protostar |
Temperature rises as star gets denser and more particles collide When hit enough, hydrogen nuclie undergo nuclear fusion |
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Main Sequence Star |
Long stable period where outward pressure from fusion = inward pressure from gravity Several billion years |
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Red/Super giant |
Hydrogen runs out and the star swells Surface cools (hense the red colour) Fusion of elements as heavy as iron occurs |
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White + Black dwarf |
W- red giant becomes unstable, sheds out layer of dust as far, leaves behind hot solid dense core B- white dwarf cools and emits less and less energy |
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Supernova |
Red super giant does more fusion and then explodes as a supernova, forming elements heavier than iron and ejecting them into the universe as new planets and stars |
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Neutron Star |
Outer layer of dust and gas gone, leaving a very dense core (neutron star) |
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Black Hole |
If the star is massive enough, it will become a black hole A super dense point that not even light can escape from |
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Our solar system |
One star (the sun) Natural satellites (the moon) Artificial satellites Planets Dwarf planets |
Part of the Milky Way galaxy |
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Orbit |
Travelling in a circle - constantly changing velocity and acceleration but not speed - due to force directed towards centre (gravitational force) Instantaneous velocity is at a right angle to acceleration towards central keeps it travelling in a circle |
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Size of orbit |
Depends on an object’s speed Closer you get, stronger gravitational force Therefore needs to travel faster to remain in orbit |
In stable orbit, if speed changes, do must radia orbit Faster moving = smaller radius |
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Red shift |
Light from most distant galaxies has increased wavelength (closer to red on spectrum) More distant galaxies are moving away faster than closer ones |
SPACE IS EXPANDING |
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Big Bang |
All the matter in the universe occupied a very small space - a very dense and very hot small space Then it exploded, space started expanding and it is still expanding today |
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