The discovery of the T8.5 dwarf UGPS J0521+3640

B. Burningham, P.W. Lucas, S.K. Leggett, R. Smart, D. Baker, D.J. Pinfield, C. G. Tinney, D. Homeier, F. Allard, Z. H. Zhang, J. Gomes, A. C. Day-Jones, H.R.A. Jones, G. Kovacs, N. Lodieu, F. Marocco, D. N. Murray, B. Sipocz

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)
43 Downloads (Pure)


We have carried out a search for late-type T dwarfs in the UKIRT Infrared Deep Sky Survey Galactic Plane Survey 6th Data Release. The search yielded two persuasive candidates, both of which have been confirmed as T dwarfs. The brightest, UGPS J0521+3640, has been assigned the spectral type T8.5 and appears to lie at a distance of 7-9 pc. The fainter of the two, UGPS J0652+0324, is classified as a T5.5 dwarf and lies at an estimated distance of 28-37 pc. Warm-Spitzer observations in IRAC channels 1 and 2, taken as part of the GLIMPSE360 Legacy Survey, are available for UGPS J0521+3640 and we used these data with the near-infrared spectroscopy to estimate its properties. We find best-fitting solar metallicity BT-Settl models for T-eff = 600 and 650 K and log g = 4.5 and 5.0. These parameters suggest a mass between 14 and 32M(J) for an age between 1 and 5 Gyr. The proximity of this very cool T dwarf, and its location in the Galactic plane, makes it an ideal candidate for high-resolution adaptive optics imaging to search for cool companions.

Original languageEnglish
Pages (from-to)L90-L94
Number of pages5
JournalMonthly Notices of the Royal Astronomical Society
Issue number1
Publication statusPublished - Jun 2011


  • surveys
  • brown dwarfs
  • stars: low-mass


Dive into the research topics of 'The discovery of the T8.5 dwarf UGPS J0521+3640'. Together they form a unique fingerprint.

Cite this