High proper motion objects from the UKIDSS Galactic plane survey

Abstract

The UKIDSS Galactic Plane Survey (GPS) began in 2005 as a seven year effort to survey ~1800 deg2 of the northern Galactic plane in the J, H, and K passbands. The survey included a second epoch of K-band data, with a baseline of two to eight years, for the purpose of investigating variability and measuring proper motions.We have calculated proper motions for 167 million sources in a 900 deg2 area located at l > 60° in order to search for new high proper motion objects. Visual inspection has verified 617 high proper motion sources (>200 mas yr-1) down to K = 17, of which 153 are new discoveries. Among these, we have a new spectroscopically confirmed T5 dwarf, an additional T dwarf with estimated type T6, 13 new L dwarf candidates, and two new common proper motion systems containing ultracool dwarf candidates. We provide improved proper motions for an additional 12 high proper motion stars that were independently discovered in the WISE data set during the course of this investigation.