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

¹ Istituto Nazionale di Astrofisica, Osservatório Astronomico di Torino, Strada Osservatório 20, 10025 Pino Torinese, Italy e-mail: smart@oato.inaf.it
² Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL109AB, UK
³ Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720, USA
⁴ Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK
⁵ Joint Astronomy Centre, 660 North A'ohoku Place, Hilo, HI 96720, USA
⁶ ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei Munchen, Germany
⁷ Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK

Received: 10 November 2009
Accepted: 16 December 2009

Abstract

Aims. We demonstrate the feasibility of determining parallaxes for nearby objects with the Wide 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 mas,  mas/yr and  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 M_J, cool, 550-600 K, brown dwarf. We present a measurement of the radial velocity that is consistent with an age between 0.5 and 4.0 Gyr.