Brown Dwarf
Related Category: Astronomy: General
in astronomy, celestial body that is larger than a planet but does not have sufficient mass to convert hydrogen into helium via nuclear fusion as stars do.
Brown Dwarfs
The first clear evidence of the existence of a brown dwarf was published in 1995. The evidence consisted of observations from the large, ground-based telescopes on Mount Palomar, and an image taken by NASA's Hubble Space Telescope.
Brown Dwarf
Located 19 light-years from the sun in the constellation of Lepus, the brown dwarf star Gliese 229B orbits the star red dwarf Gliese 229.
Brown dwarf cooks up a storm
...A team led by astronomers from the University of Toronto have observed noticeable changes in brightness of a nearby brown dwarf, roughly 40 light years away, indicating the presence of a gigantic storm...
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Brown dwarfs within 10 parsecs
Robert Hurt, IPAC, NASA
Larger illustration: Sol; M,L,T dwarfs; & Jupiter.
Brown dwarf
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History
A brown dwarf is a stellar object that has characteristics of both a star and a planet.
Brown Dwarf
A failed star which is not massive enough to ignite thermonuclear fusion in the core. According to stellar models, the maximum mass a brown dwarf can have is .
Brown dwarfs are small-size objects, believed to result from condensations of fragments of molecular clouds. A brown dwarf has a small mass, too low to ignite nuclear .
This weird "unseen crazy aunt in the attic" has been named Nemesis by astronomers. It's thought to be a brown dwarf that spins around the Sun in an orbit so large it is measured in light years equivalent to about 6,000 billion miles.
Brown Dwarfs
Brown dwarfs are objects which are too large to be called planets and too small to be stars.
brown dwarf Remnant of a fragment of collapsing gas and dust that did not contain enough mass to initiate core nuclear fusion.
Brown Dwarfs
Brown dwarfs are objects which, like stars, formed out of dense clumps of gas and dust inside molecular clouds. However, unlike stars, they are not massive enough for nuclear fusion to have started in their cores.
brown dwarf
a gaseous object that forms like a star but lacks the necessary mass to sustain nuclear fusion in its core; a body intermediate in mass between a star and planet
buckyball ...
Brown Dwarf: Either a supermassive planet or a failed star, a brown dwarf has insufficient mass to sustain nuclear fusion.
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Brown Dwarf
A very cool, low luminosity star whose mass is not sufficient to ignite nuclear fusion.
Burster ...
Brown Dwarf - A star with too low a mass for nuclear fusion to begin in its core
C-type Asteroid - One of a class of very dark asteroids whose reflectance spectra show no absorption features due to the presence of minerals ...
BROWN DWARF - Low-mass substellar object near the minimum mass for hydrogen burning to occur in its core, which is ~0.084 MSun. Brown dwarfs heavier than 13 Jupiter masses do fuse deuterium.
Brown Dwarf
(a) A star with too little mass to ignite its hydrogen-1 fuel. If brown dwarfs exist, they shine faint red for a time, as they convert gravitational energy into heat, and then fade and cool.
Brown dwarf- a "failed star" in the sense that when it was finished forming, it did not have enough mass to begin fusion; it does not shine as a star does, ...
BROWN DWARF
A brown dwarf is a "star" whose mass is too small to have nuclear fusion occur at its core (the temperature and pressure at its core are insufficient for fusion) - a failed star. A brown dwarf is not very luminous.
THE BROWN DWARF COMPANION
In addition to its planet, 54 Piscium also has a low-mass substar companion, a brown dwarf called 54 Psc B (or HD 3651 B) located 43 seconds of arc away, ...
* ROGUE BROWN DWARF: Another note from DISCOVERY CHANNEL Online reported that British astronomers using the UK Infrared Telescope (UKIRT) -- a hefty 3.
Brown dwarf companions, though, have usually been thought of as forming in the same way stellar companions do (and these are quite common). They do not go to the trouble of building up from small objects.
Brown Dwarf
An object too small to be an ordinary star because it cannot produce enough energy by fusion in its core to compensate for the radiative energy it loses from its surface. A brown dwarf has a mass less than 0.08 times that of the Sun.
Brown dwarf orbiting a red dwarf star. Shining from energy generated by gravitational contraction, not through nuclear reactions like stars.
How Far Away:
18 light years ...
Brown dwarf : ``failed'' star, Mstar < 0.08 Msun, no fusion
HII regions, O&B stars ionize H, pink (H-alpha) color
Star winds & supernovae remove gas ---
young star cluster
Star Structure :
Energy source : p--p chain; CNO cycle ...
brown dwarf
A star whose omass is too low to ignite nuclear fusion. Heated by contraction.
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Brown dwarf: A star that never became massive enough to start core hydrogen burning.
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Brown dwarfs are starlike objects that, because of their extremely small size, never achieve the necessary conditions in their cores to sustain the nuclear fusion that powers normal stars.
brown dwarf Clouds of collapsing gas and dust that did not contain enough mass to initiate core nuclear fusion. Such objects are then frozen somewhere along their pre-main sequence contraction phase, continually cooling into compact dark objects.
Brown dwarfs are mysterious objects that form out of clouds of gas and dust. They are similar to stars. But their mass is too small to cause them to shine like stars On the other hand, their mass is too large to call them planets.
brown dwarf - (n.)
An object substantially (~13 x) larger than Jupiter but with a mass no more than 40 percent that of the Sun.
A brown dwarf star around which orbits the first extrasolar planet ever to be directly photographed. 2M1207 (full catalog designation: 2MASSWJ1207334-393254) lies in the constellation Hydra at a distance of 228 light-years.
Y: brown dwarfs that are cooler than T-dwarfs, (theoretical)
Carbon related late giant star classes ...
EPE
Brown dwarfs
There is currently one known planet orbiting a brown dwarf.
A Small Brown Dwarf Star
One of the smallest star's ever observed is that of the brown dwarf orbiting a cool red star Gliese 229, called Gliese 229B (GL229B). But is it really a star?
See also: Sub-brown dwarf
Class Y dwarfs are expected to be much cooler than T-dwarfs. Although they have been modelled[39], there is no well-defined spectral sequence yet with prototypes.
(141k jpg; 38k jpg; more; The Noble Dane: Images of Tycho Brahe, from the Museum of the History of Science in Oxford) brown dwarf An object between 0.013 and 0.
The greater the speed of the object, the greater the blueshift will be. brown dwarf object formed from the gravitational collapse of a gas cloud just as a star is but having too little mass (less than 0.08 solar masses) to undergo nuclear ...
Brown Dwarfs
Believe it or not, there are some stars out there that are more boring than the Sun. This would be those that have very low masses compared to the Sun. How low?
The same lensing calculations also apply locally, forming the heart of several massive projects aimed at seeing what the contribution of white dwarfs, red dwarfs, brown dwarfs, and loose "rogue" planets is to the Milky Way's mass.
If brown dwarfs exist, they shine faint red for a time, as they convert gravitational energy into heat, and then fade and cool. Their masses range from 1 to 8 percent of the Sun's mass. [C95] ...
Thousands of young stars may need to have their ages re-adjusted by as much as 20 percent for average-sized stars and 50 percent for low-mass stars like brown dwarfs, the scientists estimated.
Objects just below this limit are called brown dwarfs, because, while they cannot fuse hydrogen, they can fuse deuterium, the two-nucleon isotope of hydrogen.
Examples would be brown dwarfs (starlike objects too low in mass to fuse hydrogen in their interiors), dead white dwarfs, neutron stars, and black holes.
If the protostar is slightly more massive than a planet, but not massive enough to burn its nuclear fuels, it becomes a brown dwarf, which is very dim and hence very difficult to find.
It is doomed to remain a dark, dismal stellar failure - a brown dwarf star. A larger lump becomes a large star, so hot and bright that it burns itself out in a few tens of millions of years.
In some protostars, contraction remains the only source of energy; these are brown dwarfs, and they die away slowly, over hundreds of billions of years.
This image shows the orbits of an L-type star and its brown dwarf companion. The period is about ten years. Using the data from these images astronomers measured the mass of the L-type star to be about 8.5% that of our Sun and the brown dwarf to be 6.
In 2003, astronomers announced that epsilon Indi was accompanied by a brown dwarf. It was later discovered that the brown dwarf was actually a binary system.
82 light-years away and is one of the closest stars to Earth. It is a orange dwarf with a pair of brown dwarfs orbiting it. Epsilon Indi is also notable as an object of interest in SETI (Search for Extra-Terrestrial Intelligence) studies.
Passing galactic visitors, such as molecular clouds or brown dwarfs, may then disturb these clouds and send comets in toward the realm of the planets. The first such comets were discovered in the Kuiper cloud in 1992; by 1996, 31 had been found.
massive compact halo objects (NASA Thesaurus) Objects, such as brown dwarfs, black holes, and massive planets, hypothesized to account for the dark matter in the halo of the Milky Way.
 See also: Dwarf, Planet, Light, Mass, Star
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