Sub-brown dwarf

A size comparison between our Sun, a young sub-brown dwarf, and Jupiter. As the sub-brown dwarf ages, it will gradually cool and shrink.

Sub-brown dwarf is a planetary-mass object whose mass is smaller than the low-mass cut-off for brown dwarfs (around 13 times the mass of Jupiter). Unlike proper brown dwarfs, they are not massive enough to fuse deuterium. Sub-brown dwarfs are formed in the manner of stars, through the collapse of a gas cloud, and not through accretion or core collapse from a circumstellar disc. The distinction between a sub-brown dwarf and a planet is unclear; astronomers are divided into two camps as whether to consider the formation process of a planet as part of its division in classification.^[1]

An alternate definition involves the same mass range (less than a brown dwarf, but in the planetary range), but is free of gravitational attachment with any star. These are generally referred to as free-floating planets. This usage is in the IAU Extrasolar Planets provisional definition of a planet.^[2]

[edit] List of suspected sub-brown dwarfs

• 2M1207b
• SCR 1845-6357 B
• Cha 110913-773444
• OTS 44

[edit] See also

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• Planetar (astronomy)
• Interstellar planetary mass object
• Giant planet
• Red dwarf

[edit] References

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