• DOI:10.1111/j.1745-3933.2010.00927.x
• Corpus ID: 16032606

The discovery of a very cool, very nearby brown dwarf in the Galactic plane

@article{Lucas2010TheDO,
  title={The discovery of a very cool, very nearby brown dwarf in the Galactic plane},
  author={Philip W. Lucas and Christopher G. Tinney and Ben Burningham and Sandy K. Leggett and David J. Pinfield and Richard L. Smart and Hugh R. A. Jones and Federico Marocco and Robert J. Barber and Sergei N. Yurchenko and Jonathan Tennyson and Miki Ishii and Motohide Tamura and Avril C. Day-Jones and A J Adamson and France Allard and Derek Homeier . University of Hertfordshire and University of New South Wales and Gemini Observatory and Osservatorio astronomico di Torino and University College London and Tech. U. Dresden and Subaru Telescope and National Astronomical Observatory Japan and Universidad Catolica de Chile and Joint Astronomy Centre and Universit́e de Lyon and Institut fur Astrophysik Gottingen},
  journal={Monthly Notices of the Royal Astronomical Society: Letters},
  year={2010},
  volume={408}
}

• P. Lucas, C. Tinney, +25 authors I. Gottingen
• Published 2 April 2010
• Physics
• Monthly Notices of the Royal Astronomical Society: Letters

We report the discovery of a very cool, isolated brown dwarf, UGPS 0722-05, with the United Kingdom Infrared Telescope Deep Sky Survey (UKIDSS) Galactic Plane Survey. The near-infrared spectrum displays deeper H2O and CH4 troughs than the coolest known T dwarfs and an unidentified absorption feature at 1.275 mu m. We provisionally classify the object as a T10 dwarf but note that it may in future come to be regarded as the first example of a new spectral type. The distance is measured by trigonometric parallax as d = 4.1(-0.5)(+0.6) pc, making it the closest known isolated brown dwarf. With the aid of Spitzer/Infrared Array Camera (IRAC) we measure H - [4.5] = 4.71. It is the coolest brown dwarf presently known - the only known T dwarf that is redder in H - [4.5] is the peculiar T7.5 dwarf SDSS J1416+13B, which is thought to be warmer and more luminous than UGPS 0722-05. Our measurement of the luminosity, aided by Gemini/T-ReCS N-band photometry, is L = 9.2 +/- 3.1 x 10(-7) L-circle dot. Using a comparison with well-studied T8.5 and T9 dwarfs we deduce T-eff = 520 +/- 40 K. This is supported by predictions of the Saumon & Marley models. With apparent magnitude J = 16.52, UGPS 0722-05 is the brightest of the similar to 90 T dwarfs discovered by UKIDSS so far. It offers opportunities for future study via high-resolution near-infrared spectroscopy and spectroscopy in the thermal infrared.