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

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

Monthly Notices of the Royal Astronomical Society, Volume 422, Issue 3, pp. 1922-1932.

Advertised on:
5
2012
Number of authors
23
IAC number of authors
1
Citations
64
Refereed citations
56
Description
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.
Related projects
Discovery of a system of super-Earths orbiting the star HD 176986 with about 5.7 and 9.2 Earth masses.
Very Low Mass Stars, Brown Dwarfs and Planets
Our goal is to study the processes that lead to the formation of low mass stars, brown dwarfs and planets and to characterize the physical properties of these objects in various evolutionary stages. Low mass stars and brown dwarfs are likely the most numerous type of objects in our Galaxy but due to their low intrinsic luminosity they are not so
Rafael
Rebolo López