Program: GN-2013A-DD-2

We propose GNIRS DDT observations to confirm the spectral type of the first T dwarf to be identified with clear halo kinematics. In addition to displaying extremely high proper-motion, our target also exhibits a number of apparently contradictory photometric properties, which may be best explained by a very low-metallicity atmosphere, as would be expected for a substellar member of the Galactic halo. As the first T subdwarf, this target represents a significant expansion of the current atmospheric parameter space and will be a prototype for future searches for substellar halo objects. Identifying unusual and groundbreaking brown dwarfs is an extremely competitive field in which several major international teams are active and it is on this basis that we request DDT.