active galaxy
Britishnoun
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A galaxy emitting unusually high quantities of radiation from an active galactic nucleus at its center. Some active galaxies emit more energy in radio wavelengths than they do visible light. Seyfert galaxies are examples of active galaxies.
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See more at galactic nucleus
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Blazars are a type of active galaxy powered by supermassive black holes that shoot out powerful, narrow jets of particles and radiation at nearly the speed of light.
From Science Daily
OJ 287 is classified as a blazar, a type of active galaxy known for its intense energy and brightness.
From Science Daily
NGC 4945 is an active galaxy about 13 million light-years away in the southern constellation Centaurus.
From Science Daily
An active galaxy has an unusually bright and variable center powered by a supermassive black hole that heats a surrounding disk of gas and dust through gravitational and frictional forces.
From Science Daily
The detection of neutrinos ostensibly coming from this active galaxy is a big deal.
From Scientific American
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Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.