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28 Cards in this Set
- Front
- Back
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The radio source ________ is located in a place consistent with the center of our Galaxy.
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Sgr A*
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Why was Herschel's strategy for mapping our Galaxy flawed?
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He relied on visual wavelengths, which are obscured by dust.
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Most of the new star formation in the Galaxy is found in the
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globular clusters.
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Between us and the Galactic Center, the Milky Way has a mass of
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100 billion Suns.
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The extent of our galaxy and our place within it was first found by Harlow Shapley with
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RR Lyrae variables in the globular clusters.
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Does a 1.5 solar mass white dwarf exist
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NO
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Which of these is not an argument for Cygnus X-1 being a black hole?
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The mass of the visible star is greater than that of the X-ray source.
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All RR Lyrae stars have about the same
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luminosity of about 100 Suns.
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A method for identifying a black hole is to
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look for its effects on a nearby companion.
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The period-luminosity relation is critical in finding distances with
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Cepheid variables.
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Which of these is not typical of the Galaxy's spiral arms
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Population II giants like orange Arcturus
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From the Sun, the distance to the Galactic Center is about
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8 kpc.
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The RR Lyrae stars all have periods of
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several hours
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A star in the instability strip of the H-R diagram would
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vary in both temperature and radius.
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Most of the mass of our Galaxy lies
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outside the luminous part of the Milky Way Galaxy.
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Which is the correct description of the Sun's location within the Milky Way?
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in the disc and about one-half a galactic radius from the center
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Galactic disks appear blue because
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O and B blue giants are much brighter than G, K, or M dwarfs.
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Which statement is true?
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The bright blue stars that dominate the sky are Population I stars.
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Which method relies on the mass of a dark object revealing its presence?
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temporary brightening of a distant star by a gravity lens
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Which of these variable stars would be classified as a Cepheid?
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a K giant with a period of 14 days
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Detailed measurements of the disk and central bulge region of our Galaxy suggest our Milky Way is a
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barred spiral galaxy.
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Which of these variable stars would be classified as a RR Lyrae?
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an F giant with a period of 14 hours
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In our location in the Milky Way, the galactic disk is only about ________ ly thick.
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1,000
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What observations suggest the mass of the Galaxy goes much farther out than its visible disc?
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the rotation curve of the outermost portions of the disc
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Density waves may explain
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he spiral arm structure of the Galaxy.
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The Galactic Year is the time for our solar system to orbit the Galaxy; it is about
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225 million years.
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As a spaceship nears an event horizon, a clock on the spaceship will be observed
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to run slowly.
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At the center of our Galaxy lies
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a black hole of millions of solar masses
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