brown dwarf


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 Here, fellow earth dwellers can access the Backyard Worlds: Planet 9 mission, which prompts users to search the realm beyond Neptune for new brown dwarfs and planets. Kelly Corbett, House Beautiful, "NASA's New Site Lets You Virtually Explore Space, DIY Slime, and Have Story Time With an Astronaut," 28 Apr. 2020 The object, known as a brown dwarf, is 33.2 light-years away from Earth. Ashley Strickland, CNN, "Astronomers clock extremely high winds on an object outside of our solar system," 9 Apr. 2020 One of those surprises included the unexpected finding of a white dwarf star that's draining the life from its brown dwarf companion, according to a new study. Ashley Strickland, CNN, "Vampire star system shows one star gorging on another," 24 Jan. 2020 In this case, the brown dwarf is 10 times less massive than the dense white dwarf. Ashley Strickland, CNN, "Vampire star system shows one star gorging on another," 24 Jan. 2020 Building off Spitzer's work studying brown dwarfs, or objects that are too large to be planets but too small to be stars, Webb can take a closer look at their cloud properties. Ashley Strickland, CNN, "This telescope is our next great detective in the universe," 31 Jan. 2020 Meanwhile, the other super-Earth, GJ229Ac, is the nearest temperate super-Earth in a system where the host star is also orbited by a brown dwarf. Ashley Strickland, CNN, "A cold Neptune and two super-Earths are among newly found exoplanets around nearby stars," 14 Jan. 2020 Water-vapor clouds have been found before in brown dwarfs, hulking objects that hover on the border between planet and star. Michael Greshko, National Geographic, "Water found on a potentially life-friendly alien planet," 11 Sep. 2019 Those brown dwarfs, unlike beta Pictoris, weren't surrounded by much gas or dust, so their new planet couldn't have formed by vacuuming up the stellar disk. Meghan Bartels,, "Twin Exoplanets Look Alike, Act Alike … But Have Completely Different Origins," 18 July 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.

See More

First Known Use of brown dwarf

1975, in the meaning defined above

Keep scrolling for more

Learn More about brown dwarf

Time Traveler for brown dwarf

Time Traveler

The first known use of brown dwarf was in 1975

See more words from the same year

Statistics for brown dwarf

Cite this Entry

“Brown dwarf.” Dictionary, Merriam-Webster, Accessed 22 Jan. 2021.

Keep scrolling for more

Comments on brown dwarf

What made you want to look up brown dwarf? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!