Brown dwarf

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Brown Dwarf, also called as sub-stellar objects, are a type of objects more massive than a planet but not massive enough to be real stars. They form in much the same process as regular stars but has not achieve the mass to begin hydrogen fusion. They are typically found accompanying a more massive star or they travel in space with a planetary system of their own.

Unlike planets though, they can undergo a limited type of nuclear fusion by fusing hydrogium, deuterium or lithium. Brown dwarfs are very conductive and therefor they are able to efficiently consume most of their fuel source for an extended period of time. There are 3 types of brown dwarf stars, type L which are the hottest and most luminous, type T and type Y which are least luminous type of brown dwarf known. The luminosity of a brown dwarf is due to the contraction which generates heat and light mostly in the infrared spectrum.

High mass lithium burning brown dwarfs are typically about 65 to 80 MJ in mass and will be able to sustain the fusion reaction for just over 100 million years. Low mass brown dwarf between 13 MJ to 65 MJ can fuse deuterium in its core, but because deuterium is very rare, they can only sustain the reaction for less than 100 million years before their entire supply is depleted. Lastly, brown dwarf with mass of between 8 MJ to 13 MJ, termed as very low mass sub stellar objects, are able to burn the fictional substance known as hydrogium. Very low mass brown dwarf has abundant supply of this substance and is able to sustain the thermonuclear reaction for as short as a few hundred million years to as long as a billion years. Mass and temperature greatly dictates the length of how long this objects can sustain the reaction, objects with less than 10 MJ are able to maintain the reaction for a billion years. Once this objects deplete their fuel source they do not collapse on their own gravity like regular stars do but rather they slowly contract and release heat until their cores are only supported by degenerate gas of electrons.

List of brown dwarfs

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