extragalactic

adjective
ex·​tra·​ga·​lac·​tic | \ ˌek-strə-gə-ˈlak-tik How to pronounce extragalactic (audio) \

Definition of extragalactic

: originating or existing outside the Milky Way galaxy also : of or relating to extragalactic space extragalactic astronomy

Examples of extragalactic in a Sentence

Recent Examples on the Web

One group looked at black holes as a possible explanation, since black holes are the brightest extragalactic radio sources in the sky. Quanta Magazine, "Whisper From the First Stars Sets Off Loud Dark Matter Debate," 29 Mar. 2018 The particle was a neutrino, electrically neutral and almost massless, which means its path could be traced back to the extragalactic event that created it. Daniel Clery, Science | AAAS, "Ghostly particle caught in polar ice ushers in new way to look at the universe," 12 July 2018 According to the theory, inflation stretched infinitesimal quantum fluctuations in those first moments to extragalactic size. Adrian Cho, Science | AAAS, "Stephen Hawking’s (almost) last paper: putting an end to the beginning of the universe," 2 May 2018 Amazon’s Alexa voice assistant for Echo is getting in on Star Wars spirit for May 4 — better known, perhaps as May the Fourth — to honor the iconic extragalactic franchise. Raisa Bruner, Time, "Now Your Alexa Will Respond to Even More Star Wars Commands for May the Fourth," 2 May 2018 One group looked at black holes as a possible explanation, since black holes are the brightest extragalactic radio sources in the sky. Liz Kruesi, WIRED, "Whisper From the First Stars Sets Off Loud Dark Matter Debate," 31 Mar. 2018 This is an example of how powerful the techniques of analysis of extragalactic microlensing can be. Jason Daley, Smithsonian, "Astronomers Spot Signs of Planets Outside the Milky Way," 6 Feb. 2018 Located in a galaxy some 3.8 billion light-years away, the extragalactic planets are too far away to be observed directly even with the biggest telescopes now in existence. David Freeman /, NBC News, "The first planets beyond the Milky Way may have been discovered," 5 Feb. 2018 According to the team, this anisotropy indicates an extragalactic origin for the cosmic particles, as many are coming from an area where the distribution of galaxies is fairly high. Dom Galeon, NBC News, "New Research Suggests Cosmic Rays Hail From Galaxies Beyond the Milky Way," 21 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'extragalactic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of extragalactic

1851, in the meaning defined above

History and Etymology for extragalactic

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Last Updated

25 Jun 2019

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The first known use of extragalactic was in 1851

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