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Question
How can the image of a single quasar be doubled? What does that tell us about the quasar's distance?Answer
This answer is hidden. It contains 157 characters.
Related questions
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Describe the reasoning leading to the idea that the number of technological civilizations in the galaxy is equal to the average lifetime of a technological civilization.
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Quasar is short for what? Is this true of all of them?
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A galaxy with a blueshift is moving ________ Earth.
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The spiral arms are blue from the presence of Population ________ stars in them.
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Why is the energy source for active nuclei like Seyferts thought to be compact?
A) The sources appear to be single stars in photos.
B) Their energy appears to be non-stellar synchrotron radiation.
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In active galaxies, their central engines may be temporarily fed by
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Why aren't there young stars in the halo?
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What advantage do radio astronomers have over optical ones in mapping the entire Milky Way?
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How did Herschel try to map our Galaxy 200 years ago, and why did he fail?
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The ________ is the spherical outer portion of the Galaxy, including the orbits of the globular clusters and most dark matter.
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Virtually the entire disk of the Galaxy has been mapped using the ________ wavelength.