brown dwarf

noun Astronomy.

a cold, dark star that is too small to initiate the nuclear reactions that generate heat and light.

QUIZZES

How Hip Is Your Lingo? Take Our Slang Quiz!

If you aren’t already skilled in slang, then this quiz can get you up to speed in no time!

Question 1 of 11

OK Boomer can be perceived as pejorative, but it is mostly considered to be _____

a slang word for astronauts that originated in the 1950s.

a comment toward the Baby Boomer generation that is humorous or ironic in usage.

an obsolete slang term about people who speak loudly.

TAKE THE QUIZ TO FIND OUT

Words nearby brown dwarf

brown coal, brown coat, brown cow, brown creeper, brown deer, brown dwarf, brown earth, brown fat, brown goods, brown hackle, brown heart

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for brown dwarf

brown dwarf

noun

a type of celestial body midway in mass between a large planet and a small star

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for brown dwarf

brown dwarf

A celestial body with insufficient mass to sustain the nuclear fusion that produces radiant energy in normal stars. It is believed that a brown dwarf is formed with enough mass to start nuclear fusion in its core, but without enough for the fusion to become self-sustaining. Theory suggests that a body with about one percent of the mass of the Sun-or ten times the mass of Jupiter-can generate this initial fusion, but that it needs at least eight percent of the Sun's mass to sustain the fusion. After the fusion ends, the dwarf still glows for a period from radiating heat, with a surface temperature of about 2,500°K (4,532°F) or less. See Note at dwarf star.