WISE J0521+1025

WISE J0521+1025 is a nearby brown dwarf of spectral type T7.5, located in the constellation Orion at approximately 21.7 ly from Earth.

At the time of discovery, it was the nearest known T dwarf in the northern sky.

History of observations
WISE J0521+1025 was discovered by Bihain et al. by selection of sources with colours typical for T dwarfs from WISE All-Sky source catalogue and checking them for high proper motion using older surveys: 2MASS, DENIS, SDSS, SSS, DSS and UKIDSS. Three objects among about ten candidates, including WISE J0521+1025, were selected for spectroscopic follow up with Large Binocular Telescope (LBT). October 9, 2012 Bihain et al. carried out follow up observations of WISE J0521+1025 with near-Infrared spectrograph LUCI 1 on LBT. June 25, 2013 Astronomy & Astrophysics received the discovery paper, which was accepted for publication 10 July 2013.

Distance
Distance of WISE J0521+1025 was estimated by Bihain et al. using mean absolute magnitudes of single T7.5 dwarfs, derived by Dupuy & Liu (2012) from trigonometric parallaxes: 5.0 ± 1.3 pc (16.3 ± 4.2 ly).