brown dwarf

noun

Definition of brown dwarf 

: a celestial object that is much smaller than a normal star and has insufficient mass to sustain nuclear fusion but that is hot enough to radiate energy especially at infrared wavelengths

Examples of brown dwarf in a Sentence

Recent Examples on the Web

The idea was first announced in a 2015 study, which focused on Scholz’s Star, a small red dwarf with an orbiting brown dwarf that lies some 20 light years away from Earth. Jason Daley, Smithsonian, "70,000 Years Ago, a Passing Star Shook Up Our Solar System," 22 Mar. 2018 Jackie Faherty, a brown dwarf researcher at the American Museum of Natural History, told Redd prior to the release of the data. Jason Daley, Smithsonian, "New Star Map Could Change Everything We Know About the Milky Way," 25 Apr. 2018 Anything between those bounds, then, should be a brown dwarf. Nola Taylor Redd, Scientific American, "It’s Full of Stars: New 3-D Milky Way Map Could Settle Debate over Who Discovered the First Exoplanet," 20 Apr. 2018 Many of these puny objects, identified by the water vapor condensing in their cool atmospheres, are brown dwarfs—failed stars that never collected enough material to ignite nuclear fusion in their cores. National Geographic, "Take a 3-D Tour of a Space Cloud Full of Baby Stars," 11 Jan. 2018 Columbia University astronomer Brian Metzger and his colleagues there and at the University of California, Berkeley, have fleshed out a more feasible explanation in which a planet or brown dwarf collided with Boyajian's star. Kimberly Cartier, Scientific American, "Have Aliens Built Huge Structures around Boyajian’s Star?," 1 May 2017 While searching for brown dwarfs, the team also netted a few objects that appear to be more like planets than nuclearly bankrupt stars. National Geographic, "Take a 3-D Tour of a Space Cloud Full of Baby Stars," 11 Jan. 2018 Since the project began, citizens have spotted 432 candidates for brown dwarfs, which are balls of gas too small to be stars but too big to be planets. Alex Stuckey, Houston Chronicle, "NASA wants your help in search for new planet beyond Pluto," 23 Feb. 2018 Schlaufman focuses on the differences between gas giants like Jupiter and brown dwarfs. David Grossman, Popular Mechanics, "New Proposed Definition of Planets Says They Can Only Get So Big," 24 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'brown dwarf.' 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 brown dwarf

1975, in the meaning defined above

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Last Updated

29 Sep 2018

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The first known use of brown dwarf was in 1975

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More from Merriam-Webster on brown dwarf

Nglish: Translation of brown dwarf for Spanish Speakers

Britannica.com: Encyclopedia article about brown dwarf

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