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In the 1790's, Sir William Herschel tried to measure the Sun's positions in our galaxy by
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Counting the density of stars in different directions along the Milky Way
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In a binary star system, an unseen component is found to have a mass of 8 solar masses. If this were a normal star, then it would be visible, so it must be a collapsed object. Theoretical considerations tell us that is must be
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A black hole
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Pulsars probably formed
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In the center of a supernova
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What quantum transition occurs inside a cool hydrogen atom to produce a 21-cm radio photon?
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An electron in the ground atomic state reverses the direction of its spin with respect to that of the photon.
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The upper limit to neutron stars (when it hits degeneracy), or the bottom limit of a black hole is
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About 3 solar masses
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Newtons law of gravity states
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Earth orbits the Sun due to a gravitational force that the sun exerts on the earth across empty space
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Where would you find a pulsar in our universe?
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Crab Nebula
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What separates a Black hole from the rest of the galaxy?
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Event Horizon
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Neutron stars are created by
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Type two supernovae - explosions of high-mass gasses.
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Stars not in halo of galaxy
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O-type stars
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What is the law of cosmic censorship?
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There can be no naked sigularities; every black hole must be surrounded by an event horizon.
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Center of Milky Way galaxy is in constellation
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Sagittarius A*
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What is Photodisintegration?
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Splitting apart of atomic nuclei by high energy gamma rays
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Crab Nebula is a
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Supernova Remnant
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Which components best outline the spiral arms of the galaxy?
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Young O and B stars, dust and gas
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