Proper motions of field L and T dwarfs

Abstract

The proper motion measurements for 143 previously known L and T dwarfs are presented. From this sample we identify and discuss eight high-velocity L dwarfs. We also find four new wide common proper motion binaries/multiple systems. Using the moving cluster methods we have also identified a number of L dwarfs that may be members of the Ursa Major (age ≈ 400 Myr), the Hyades (age ≈ 625 Myr) and the Pleiades (age ≈ 125 Myr) moving groups.