Spectroscopic Confirmation and Proper Motion Measurement of a T-Dwarf Brown Dwarf at 2 Kiloparsecs

A T5-T6 brown dwarf at a distance of 1.8-2.3 kpc from the Sun, with evidence of low metallicity ([M/H] ≤ -0.5) and a high transverse velocity of 172-214 km/s, suggesting it is likely a member of the Milky Way thick disk or halo.