CaltechAUTHORS
Published June 20, 2013 | Version Published + Accepted Version
Journal Article Open

Characterization of the nearby L/T Binary Brown Dwarf WISE J104915.57–531906.1 at 2 Pc from the Sun

Creators

  • 1. ROR icon South African Radio Astronomy Observatory
  • 2. ROR icon European Southern Observatory
  • 3. ROR icon University of Valparaíso
  • 4. ROR icon Centro de Astrobiología
  • 5. ROR icon Pontificia Universidad Católica de Chile
  • 6. ROR icon Vatican Observatory
  • 7. ROR icon Nagoya University
  • 8. ROR icon Las Campanas Observatory
  • 9. ROR icon University of Cape Town
  • 10. ROR icon Rutgers, The State University of New Jersey

Abstract

WISE J104915.57–531906.1 is a L/T brown dwarf binary located 2 pc from the Sun. The pair contains the closest known brown dwarfs and is the third closest known system, stellar or sub-stellar. We report comprehensive follow-up observations of this newly uncovered system. We have determined the spectral types of both components (L8 ± 1, for the primary, agreeing with the discovery paper; T1.5 ± 2 for the secondary, which was lacking spectroscopic type determination in the discovery paper) and, for the first time, their radial velocities (V_(rad) ~ 23.1, 19.5 km s^(–1)) using optical spectra obtained at the Southern African Large Telescope and other facilities located at the South African Astronomical Observatory (SAAO). The relative radial velocity of the two components is smaller than the range of orbital velocities for theoretically predicted masses, implying that they form a gravitationally bound system. We report resolved near-infrared JHK_S photometry from the Infrared Survey Facility telescope at the SAAO which yields colors consistent with the spectroscopically derived spectral types. The available kinematic and photometric information excludes the possibility that the object belongs to any of the known nearby young moving groups or associations. Simultaneous optical polarimetry observations taken at the SAAO 1.9 m give a non-detection with an upper limit of 0.07%. For the given spectral types and absolute magnitudes, 1 Gyr theoretical models predict masses of 0.04-0.05 M _☉ for the primary, and 0.03-0.05 M _☉ for the secondary.

Additional Information

© 2013 The American Astronomical Society. Received 2013 March 28; Accepted 2013 May 2; Published 2013 June 4. Some observations reported in this paper were obtained with the Southern African Large Telescope (SALT). All SAAO and SALT co-authors acknowledge the support from the National Research Foundation (NRF) of South Africa. This research has benefited from the MLTY dwarf compendium at http://DwarfArchives.org. We thank Adam Burgasser for making some template spectra available to us and the anonymous referee for the suggestions that helped to greatly improve the paper. R.K. and J.B. acknowledge partial support from FONDECYT through grant Nos. 1130140 and 1120601, respectively. D.M. is supported by BASAL CATA PFB-06 and FONDECYT No. 1130196.

Attached Files

Published - apj_770_2_124.pdf

Accepted Version - 1303.7171v2.pdf

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Additional details

Identifiers

Eprint ID
57879
Resolver ID
CaltechAUTHORS:20150528-123635645

Related works

Describes
http://arxiv.org/abs/1303.7171 (URL)

Funding

National Research Foundation of South Africa
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1130140
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1120601
El Centro de Astrofísica y Tecnologías Afines' (CATA)
PFB-06
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1130196

Dates

Created
2015-05-29
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field