brown dwarf

noun

Updated on: 1 Apr 2018

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

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Recent Examples of brown dwarf from the Web

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
What's the difference between a giant planet and a brown dwarf?

— david grossman, Popular Mechanics, "New Proposed Definition of Planets Says They Can Only Get So Big," 24 Jan. 2018
That’s how Bob Fletcher, a science teacher in Hobart, Tasmania, initially located the brown dwarf in the Astrophysical Journal Letters paper.

— jesse emspak, Smithsonian, "The Universe Needs You: To Help in the Hunt for Planet 9," 28 Aug. 2017
That one, co-discovered by four citizen observers, has been verified and published, and as of May 2017, 12 more brown dwarf candidates had been submitted for further observation.

— richard tribou, OrlandoSentinel.com, "Researchers cite more evidence on likely 'Planet Nine' existence," 16 Oct. 2017

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.