brown dwarf
noun
: 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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The two brown dwarfs, both 60 to 80 times as massive as Jupiter, orbit each other so tightly that the entire ZTF J1239 system would fit between Earth and the moon.
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Robert Lea, Space.com, 23 Mar. 2026
After around a trillion years, total, have elapsed since the hot Big Bang, there won’t really be any galaxies left to view other than Milkdromeda, and the star-formation rate may be effectively zero, save for the rare merger of brown dwarfs that then cross the mass threshold to become stars.
—Big Think, 13 Mar. 2026
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Robert Lea, Space.com, 23 Mar. 2026
After around a trillion years, total, have elapsed since the hot Big Bang, there won’t really be any galaxies left to view other than Milkdromeda, and the star-formation rate may be effectively zero, save for the rare merger of brown dwarfs that then cross the mass threshold to become stars.
—Big Think, 13 Mar. 2026
See All Example Sentences for brown dwarf
Cite this Entry
“Brown dwarf.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/brown%20dwarf. Accessed 26 Mar. 2026.
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