Luhman 16A and B are an interesting and well studied binary brown dwarf system. http://exoplanet.eu/catalog/luhman_16_a/
, this shows the pair have orbital period about 27.5 years. Astrometry was used to determine accurate distance and masses for the pair too from Gaia DR2, https://www.aanda.org/articles/aa/abs/2018/10/aa33626-18/aa33626-18.html
"Using Gaia DR2 as astrometric reference field, we derived the absolute proper motion and updated the absolute parallax of the binary to 501.557 ± 0.082 mas. We refined the individual dynamical masses of LUH 16 to 33.5 ± 0.3 M Jup (component A) and 28.6 ± 0.3 M Jup (component B), which corresponds to a relative precision of ∼1% and is three to four times more precise than previous estimates."
A parallax of 501.557 mas is 6.5 LY distance or 1.994 pc. Some cool, geeky stats