Journal Article

Discovery of the benchmark metal-poor T8 dwarf BD +01° 2920B

D. J. Pinfield, B. Burningham, N. Lodieu, S. K. Leggett, C. G. Tinney, L. van Spaandonk, F. Marocco, R. Smart, J. Gomes, L. Smith, P. W. Lucas, A. C. Day-Jones, D. N. Murray, A. C. Katsiyannis, S. Catalan, C. Cardoso, J. R. A. Clarke, S. Folkes, M. C. Gálvez-Ortiz, D. Homeier, J. S. Jenkins, H. R. A. Jones and Z. H. Zhang

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 422, issue 3, pages 1922-1932
Published in print May 2012 | ISSN: 0035-8711
Published online May 2012 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2012.20549.x
Discovery of the benchmark metal-poor T8 dwarf BD +01° 2920B

Show Summary Details

Preview

We have searched the Wide-field Infrared Survey Explorer first data release for widely separated (≤10 000 au) late T dwarf companions to Hipparcos and Gliese stars. We have discovered a new binary system containing a K-band suppressed T8p dwarf WISEP J142320.86+011638.1 and the mildly metal poor ([Fe/H] =−0.38 ± 0.06) primary BD +01° 2920 (HIP 70319), a G1 dwarf at a distance of 17.2 pc. This new benchmark has Teff= 680 ± 55 K and a mass of 20–50MJup. Its spectral properties are well modelled except for known discrepancies in the Y and K bands. Based on the well-determined metallicity of its companion, the properties of BD +01° 2920B imply that the currently known T dwarfs are dominated by young low-mass objects. We also present an accurate proper motion for the T8.5 dwarf WISEP J075003.84+272544.8.

Keywords: surveys; brown dwarfs; stars: low-mass

Journal Article.  8020 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.