Topic 8 Space Physics Flashcards Preview

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Flashcards in Topic 8 Space Physics Deck (19):


How stars initially form and is a cloud of dust and gas



The gravity pulls the dust together to form a protostar. The star gets denser and so does the temperature when the temperature gets high enough hydrogen nuclei undergo nuclear fusion to form helium nuclei giving huge amounts of energy


Main sequence stars

A long stable period when the outward pressure caused by nuclear fusion balances with the force of gravity pushing inwards and lasts for several billion years


Red super giants and red giants

When the hydrogen runs out the star swells to a red super giant or red giant and it becomes red as it is cooler.


White dwarfs

Small to medium sized star become unstable and eject its outer layer of dust and gas. Leaving a hot dense solid core


Black dwarfs

A white dwarf cools down emitting less energy once it no longer emits a significant amount of energy it becomes a black dwarf



Big stars will glow brightly as fusion increases and expand and contract and eventually explode forming elements heavier then iron these form new plants and stars


Neutron stars and black holes

The exploding supernova throws the outer layers of dust and gas into space leaving a dense core called a neutron star or if it is big enough it will become a black hole


The cycle of a small star

Cloud of dust and gas- main sequence star- red giant- white dwarf- black dwarf


The cycle of a bigger star

Cloud of dust and gas- protostar- main sequence star- red super giant- supernova- neutron star or black hole



Large objects that orbit a sun. Have to be large enough to “clear their neighbourhood” so they pull in any nearby objects apart from natural satellites


Dwarf planets

Planet like objects that orbit the sun but don’t meet all the rules for being a planet



Orbit planets and a type of natural satellite


Artificial satellites

Satellites that were created by humans


The size of the orbit depends on the objects speed

The closer to a planet the stronger the gravitational force. The stronger the force the faster it has to travel to stay in orbit. In a stable orbit if the speed changes so does the size of the object. Faster objects will have a smaller radius of their orbit


Gravity creating orbits

Constantly changing direction so velocity as well. The force is directed towards the centre. It keeps accelerating towards what is circling it but the instantaneous velocity Keeps it travelling in a circle


The red-shift the expanding universe

Light from the most distant galaxies have an increased wavelength. So the wavelength has moved to the red end of the spectrum suggesting the source is moving further away


Suggesting the universe started with the Big Bang

Initially the universe occupied a small area so was dense and hot. Then it exploded causing an expansion and it is still going on


New evidence which could change theories

The Big Bang is the best theory at this point in time. Observations of the 1998 supernova show distant galaxies are moving away faster and faster. The universe is thought to be made of dark matter and dark energy these are thought to be responsible for the expansion of the universe