Active galaxies

http://astrothesaurus.org/uat/17

dcterms modified equal to or less than 2020-11-03T17:54:29.591Zequal to or more than 2020-11-03T17:54:29.591Z
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http://astrothesaurus.org/uat/573 original
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definition A galaxy that produces huge amounts of energy at its center, which cannot be attributed to normal processes from stars, interstellar medium, and their interactions. There are several types of active galaxies: Seyfert galaxies, quasars, and blazars. All of these objects show brightness variations, some as short as 3 hours. These fluctuations indicate a relatively very small size for the central object, because an object cannot vary in brightness faster than light can travel across it. For example, an object that is one light-year in diameter cannot vary significantly in brightness over a period of less than one year.
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http://astrothesaurus.org/uat/1006 original
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http://astrothesaurus.org/uat/1343 original
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http://astrothesaurus.org/uat/1570 original
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http://astrothesaurus.org/uat/158 original
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http://astrothesaurus.org/uat/16 original
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http://astrothesaurus.org/uat/164 original
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17 original
http://astrothesaurus.org/uat/2017 original
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http://astrothesaurus.org/uat/701 original
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http://astrothesaurus.org/uat/925 original
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17 original
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contributor AAS_Frey.Katie original