Spectral binaries of brown dwarfs

Screen shot 2013-08-22 at 2.02.36 AMHow do brown dwarfs form? Some theories point to a star-like birth, accreting material from a molecular cloud, while some others point to a planet-like formation from a pre-stellar disk. Either way, the essential mechanisms for brown dwarf formation remain under debate by theorists. Given the astronomical timelines of star formation (1-10 million years), we cannot witness the formation process in action, but we can study its consequences on the statistical properties of the systems created.

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Observations of Luhman 16AB: A Brown Dwarf Binary at 2 pc

Early in March 2013, Kevin Luhman announced his discovery of a pair of brown dwarfs only 2 pc (6 light-years) from the Sun, the 3rd closest system to us after the α/Proxima Centauri system and Barnard’s Star. This remarkable find was buried in survey data going back 35 years, but elucidated with the mid-infrared sensitivity of the Wide-field Infrared Survey Explorer (WISE) and the object’s very high proper motion (2.8 arcseconds/year, or just under 0.1 degrees/century).  Using optical spectroscopy, Luhman found that the brighter of the two components had a late-L spectral type, suggesting that the system might straddle the transition between L dwarf and T dwarf spectral classes.  Knowing home much we like this really cool transition, we jumped into action.

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