Unified Astronomy Thesaurus

Last uploaded: June 20, 2024
Preferred Name

Brown dwarfs

Synonyms

Brown dwarf stars

Definitions

A star-like object whose mass is too small to sustain hydrogen fusion in its interior and become a star. Brown dwarfs are substellar objects and occupy an intermediate regime between those of stars and giant planets. With a mass less than 0.08 times that of the Sun (about 80 Jupiter masses), nuclear reactions in the core of brown dwarfs are limited to the transformation of deuterium into Helium-3. The reason is that the cores of these objects are supported against gravitational collapse by electron degeneracy pressure (at early spectral types) and Coulomb pressure (at later spectral types). Brown dwarfs, as ever cooling objects, will have late M dwarf spectral types within a few Myrs of their formation and gradually evolve as L, T and Y dwarfs brown dwarf cooling. As late-M and early-L dwarfs, they overlap in temperature with the cool end of the stellar main sequence (M dwarf, L dwarf, T dwarf, Y dwarf). In contrast to the OBAFGKM sequence, the M-L-T-Y sequence is an evolutionary one.

ID

http://astrothesaurus.org/uat/185

altLabel

Brown dwarf stars

Brown dwarf

broader

http://astrothesaurus.org/uat/2052

contributor

http://editor.vocabs.ands.org.au/user/AAS_Frey.Katie_Admin

http://editor.vocabs.ands.org.au/user/AAS_Frey.Katie

definition

A star-like object whose mass is too small to sustain hydrogen fusion in its interior and become a star. Brown dwarfs are substellar objects and occupy an intermediate regime between those of stars and giant planets. With a mass less than 0.08 times that of the Sun (about 80 Jupiter masses), nuclear reactions in the core of brown dwarfs are limited to the transformation of deuterium into Helium-3. The reason is that the cores of these objects are supported against gravitational collapse by electron degeneracy pressure (at early spectral types) and Coulomb pressure (at later spectral types). Brown dwarfs, as ever cooling objects, will have late M dwarf spectral types within a few Myrs of their formation and gradually evolve as L, T and Y dwarfs brown dwarf cooling. As late-M and early-L dwarfs, they overlap in temperature with the cool end of the stellar main sequence (M dwarf, L dwarf, T dwarf, Y dwarf). In contrast to the OBAFGKM sequence, the M-L-T-Y sequence is an evolutionary one.

modified

2020-10-26T19:23:35.375Z

2021-09-27T15:41:15.173Z

narrower

http://astrothesaurus.org/uat/1679

http://astrothesaurus.org/uat/894

http://astrothesaurus.org/uat/1827

http://astrothesaurus.org/uat/1680

http://astrothesaurus.org/uat/896

prefLabel

Brown dwarves

Brown dwarfs

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