With a distance of 2.0±0.15 pc, WISE 1049−5319 is the closest neighbor of the Sun that has been found in nearly a century (Henderson 1839; Barnard 1916; Adams & Joy 1917; Voˆute 1917). It is only slightly more distant than Barnard’s star, which is the second nearest known system (1.834±0.001 pc, Benedict et al. 1999). The low galactic latitude of WISE 1049−5319 (l = 5◦) is likely the reason why it was not found in previous surveys for nearby brown dwarfs, which have tended to avoid the galactic plane. Because of its proximity to the Sun, WISE 1049−5319 is a unique target for a variety of studies, such as direct imaging and radial velocity searches for planets.

We present the results of an intense photometric monitoring in the near-infrared (~0.9 microns) with the TRAPPIST robotic telescope of the newly discovered binary brown dwarf WISE J104915.57-531906.1, the third closest system to the Sun at a distance of only 2 pc. Our twelve nights of photometric time-series reveal a quasi-periodic (P = 4.87+-0.01 h) variability with a maximal peak-peak amplitude of ~11% and strong night-to-night evolution. We attribute this variability to the rotational modulation of fast-evolving weather patterns in the atmosphere of the coolest component (~T1-type) of the binary, in agreement with the cloud fragmentation mechanism proposed to drive the spectroscopic morphologies of brown dwarfs at the L/T transition. No periodic signal is detected for the hottest component (~L8-type). For both brown dwarfs, our data allow us to firmly discard any unique transit during our observations for planets >= 2 Rearth. For orbital periods smaller than ~9.5 h, transiting planets are excluded down to an Earth-size.

And finally, originally designated as WISE 1049-5319, most everyone now seems to be settling on the name Luhman 16 for this system.

I'm still not sure who Luhman is!

And first weather map of brown dwarf WISE J104915.57-531906.1B, which is informally known as Luhman 16B:

There's a quite strong hint of bands in those images. But not the equatorial ones we might expect, they rather seem to go from pole to pole

I bet the north-south elongation of the features near the equator is just an artifact of the technique- they probably just can't discriminate latitudes near the equator.

John