Published November 1, 2013 | Version v1
Journal article

THE EXEMPLAR T8 SUBDWARF COMPANION OF WOLF 1130

  • 1. Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States)
  • 2. Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)
  • 3. Department of Physics and Astronomy, MS 111, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606-3328 (United States)
  • 4. Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)
  • 5. NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

Description

We have discovered a wide separation (188.''5) T8 subdwarf companion to the sdM1.5+WD binary Wolf 1130. Companionship of WISE J200520.38+542433.9 is verified through common proper motion over a ∼3 yr baseline. Wolf 1130 is located 15.83 ± 0.96 pc from the Sun, placing the brown dwarf at a projected separation of ∼3000 AU. Near-infrared colors and medium resolution (R ≈ 2000-4000) spectroscopy establish the uniqueness of this system as a high-gravity, low-metallicity benchmark. Although there are a number of low-metallicity T dwarfs in the literature, WISE J200520.38+542433.9 has the most extreme inferred metallicity to date with [Fe/H] = –0.64 ± 0.17 based on Wolf 1130. Model comparisons to this exemplar late-type subdwarf support it having an old age, a low metallicity, and a small radius. However, the spectroscopic peculiarities of WISE J200520.38+542433.9 underscore the importance of developing the low-metallicity parameter space of the most current atmospheric models

Availability note (English)

Available from http://dx.doi.org/10.1088/0004-637X/777/1/36

Additional details

Identifiers

Publishing Information

Journal Title
Astrophysical Journal
Journal Volume
777
Journal Issue
1
Journal Page Range
[12 p.]
ISSN
0004-637X
CODEN
ASJOAB