The distance to the cool T9 brown dwarf ULAS J003402.77-005206.7

TL;DR

This paper demonstrates how to determine parallaxes for nearby brown dwarfs using UKIRT data, providing physical parameters for one of the coolest known brown dwarfs and confirming its distance and age.

Contribution

It introduces a method for parallax measurement using UKIRT data and applies it to a very cool brown dwarf, deriving its physical properties and age.

Findings

Parallax of 79.6 +/- 3.8 mas for ULAS J003402.77-005206.7

Distance consistent with a 1-2 Gyr, 13-20 MJ, 550-600K brown dwarf

Radial velocity measurement supports an age between 0.5 and 4.0 Gyr

Abstract

Aims. We demonstrate the feasibility of determining parallaxes for nearby objects with theWide Field Camera on the United Kingdom Infrared Telescope (UKIRT) using the UKIRT Infrared Deep Sky Survey as a first epoch. We determine physical parameters for ULAS J003402.77-005206.7, one of the coolest brown dwarfs currently known, using atmospheric and evolutionary models with the distance found here. Methods. Observations over the period 10/2005 to 07/2009 were pipeline processed at the Cambridge Astronomical Survey Unit and combined to produce a parallax and proper motion using standard procedures. Results. We determined pi = 79.6 +/- 3.8 mas, mura = -20.0 +/- 3.7 mas/yr and mudec = -363.8 +/- 4.3 mas/yr for ULAS J003402.77-005206.7. Conclusions. We have made a direct parallax determination for one of the coolest objects outside of the solar system. The distance is consistent with a relatively young, 1 - 2 Gyr, low mass, 13 - 20 MJ, cool, 550-600K, brown dwarf. We present a measurement of the radial velocity that is consistent with an age between 0.5 and 4.0 Gyr.