| 释义 |
brown dwarf, n. Astron.
Brit. |ˌbraʊn ˈdwɔːf|, U.S. |ˌbraʊn ˈd(w)ɔ(ə)rf|
[‹ brown adj. + dwarf n., after red dwarf n.]
A celestial object intermediate in mass between a giant planet and a star, too small to sustain the fusion of hydrogen nuclei and shining (if at all) only because of deuterium fusion resulting from heat generated by gravitational contraction.
The upper limit for the mass of a brown dwarf is thought to be about 0.08 solar mass.
1975J. C. Tarter (title of Ph.D. thesis, Univ. of Calif., Berkeley) Brown dwarf stars and how long they grew old. 1988J. Trefil Dark Side of Universe ix. 122 Baryonic dark matter could take many forms... It could be brown dwarves (small stars that barely give off any radiation) or even black holes. 1998Mod. Astronomer Mar. 8/1 Indications are that Proxima may be harbouring a substellar companion called a brown dwarf. 2000Denver Post 10 Sept. a43/1 Brown dwarfs are really dim bulbs: failed stars too low in mass to burn hydrogen and shine, too big to be planets, and devilishly difficult to detect. |