Proper motions of field L and T dwarfs -II

TL;DR

This study measures proper motions of 126 L and T dwarfs using multiple telescopes, identifying new moving group members and refining the L dwarf sequence.

Contribution

It provides new proper motion data for L and T dwarfs, discovering potential group memberships and refining existing dwarf sequences.

Findings

Identified new members of Hyades, Ursa Major, and Pleiades groups.

Discovered two L dwarfs with M dwarf companions.

Refined the L dwarf sequence for Ursa Major.

Abstract

By using images taken with WFCAM on UKIRT and SofI on the NTT and combining them with 2MASS we have measured proper motions for 126 L and T dwarfs in the dwarf archive. Two of these L dwarfs appear to have M dwarf common proper motion companions, and 2 also appear to be high velocity dwarfs, indicating possible membership of the thick disc. We have also compared the motion of these 126 objects to that of numerous moving groups, and have identified new members of the Hyades, Ursa Major and Pleiades moving groups. These new objects, as well as those identified in Jameson et al. (2008) have allowed us to refine the L dwarf sequence for Ursa Major that was defined by Jameson et al. (2008).