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16 Cards in this Set
- Front
- Back
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What is the closest star, aside from our sun, to our solar system?
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Proxima Centauri
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What is stellar equilibrium?
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When the pressure of radiation goes outward and the force of gravity goes inwards.
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What is the H-R Diagram? What does it measure/what type of information does it provide? Where are most stars located on it?
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The surface temperature of stars against their luminosity, or the total amout of energy they give off each second; Main Sequence
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What is the universe made of?
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73% dark energy, 23% dark matter, 4% other
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What happens when a star reaches 10,000,000 degrees Celcius?
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Nuclear Fusion begins
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Describe the main-sequence stage in a star's life?
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2nd stage in star's life cycle. longest stage; can last from 10 million years to hundreds of billions of years; example is the sun
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What is the nebula stage of a star's life? When does it occur?
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The stage that starts the formation of the star. Occurs when an outside force compresses the cloud some of the particles move close to each other and are pulled together by gravity.
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What is the difference between a nebula and a planatary nebula?
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In a planatary nebula it is a cloud of gas and dust that leaves the star when a star dies, and a nebula is a cloud of gas and dust that the star forms from.
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Name the three types of galaxies?
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Spiral Galaxy, Irregular Galaxy, Elliptical Galaxy
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What is a nova?
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A large explosion that releases energy and stellar material into space.
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What is the Big Bang Theory? When is the Big Bang said to have occured?
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It is when all matter and energy that make up the universe was compressed into an extremely small volume; exploded and began expanding in all directions; occured around 14 billions years ago.
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What is a neutron star? What are some of it's defining charecteristics?
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A star that has collapsed and the atoms are smashed together; very small; very fast; spins very fast;
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What is a white dwarf?
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A hot extremely dense core of matter; left over from a Red Giant; Last for billions of years
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What type of galaxy is the Milky Way?
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Spiral Galaxy
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What is cosmic background radiation? When did it form? What is it's current temperature?
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Low levels of radiation; uniformly detected from every direction in space; considered reminant of Big Bang; Now about -270 degrees Celcius.
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What is currently happening to the universe? Why is it happening?
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It is expanding because of dark energy that is rapidly expanding the universe because it opposes gravity
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