History
Brown dwarfs were originally called black dwarfs, and were classified as dark subzvezdnye objects floating freely in space and have too little mass to sustain stable thermonuclear reactions. Currently, the notion of a black dwarf is a very different meaning.
In early models of the structure of stars, it was thought that for the course of fusion reactions mass stars should be at least 80 times more mass of Jupiter (or 0.08 solar masses). The hypothesis of the existence of dense zvezdopodobnyh object with a mass less than the specified (brown dwarfs) was launched in the early 60-ies of the XX-th century. It was believed that their education has in many ways like a normal star formation, but found it very difficult, because they practically do not emit visible light. The most significant emission of brown dwarfs observed in the infrared range.
But for several decades, ground-based telescopes working in this range have very low accuracy and therefore were unable to find brown dwarfs. Later, it was suggested that, depending on the components involved in the formation of stars, the critical mass necessary for the course of the same as in normal star thermonuclear fusion of hydrogen to helium, at 75 Jupiter masses. Subzvezdnye objects rather quickly formed compression nebula may have a mass less than 13 Jupiter masses. They even deleted the course of any fusion reactions.
Since 1995, when it was first confirmed the existence of brown dwarf was found over hundreds of similar objects. It is believed that they constitute the majority of space objects in the Milky Way. Most of them are coming to the Earth - the components of multiple star ? Indians Ba and Bb, a pair of dwarfs, located at a distance of 12 light-years from the Sun.
In 2006 the first time been able to directly measure the masses of two brown dwarfs (in the dual system), which were equal to 57 and 36 Jupiter masses.