Cool Stars 14 - Submitted Abstract # 406 This version created on 1 November 2006 Discovery of a nearby L-T transition object in the Southern Galactic plane Stuart Folkes, University of Hertfordshire David Pinfield, University of Hertfordshire Tim Kendall, University of Hertfordshire Hugh Jones, University of Hertfordshire We present the discovery of 2MASSJ11263991-5003550 identified as part of an ongoing survey to discover ultra-cool dwarfs in the Southern Galactic Plane, using data from the 2MASS and SuperCOSMOS Sky Surveys. Strong FeH and H2O features in the near-infrared JH-band spectrum reveal characteristics seen in both mid-L and early-T dwarfs. We suggest these may be attributable to holes in the condensate cloud layers in the atmosphere of a single sub-stellar object. We estimate a spectral type of T0 +/- 1.5, measure a large proper-motion of µ=1.65" ± 0.03" yr, and a spectrophotometric distance of ~10pc making this object the nearest easily observable single early T-dwarf/L-T transition object in the southern hemisphere. ----------------------------------