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.
Astronomers led by Justin Kader have now observed this process in action in a nearby active galaxy known as VV 340a.
From Science Daily ● Jan. 19, 2026
OJ 287 is classified as a blazar, a type of active galaxy known for its intense energy and brightness.
From Science Daily ● Oct. 14, 2025
The detection of neutrinos ostensibly coming from this active galaxy is a big deal.
From Scientific American ● Dec. 20, 2022
“Where exactly in the active galaxy, the neutrinos are produced will be a matter of debate,” he added in an email.
From New York Times ● Jul. 12, 2018
Could the Milky Way ever become an active galaxy?
From Textbooks ● Oct. 13, 2016
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.