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Title: The first allwise proper motion discovery: Wisea J070720.50+170532.7

While quality checking a new motion-aware co-addition of all 12.5 months of Wide-field Infrared Survey Explorer (WISE) data, we found that the source WISE J070720.48+170533.0 moved 0.''9 in six months. Backtracking this motion allowed us to identify this source as 2MASS J07071961+1705464, with several entries in the USNO B catalog. An astrometric fit to these archival data gives a proper motion of μ = 1793 ± 2 mas yr{sup –1} and a parallax of piv = 35 ± 42 mas. Photometry from WISE, 2MASS, and the POSS can be fit reasonably well by a blackbody with T = 3658 K and an angular radius of 4.36 × 10{sup –11} radians. No clear evidence of H{sub 2} collision-induced absorption is seen in the near-infrared. An optical spectrum shows broad deep CaH bands at 638 and 690 nm, broad deep Na D at 598.2 nm, and weak or absent TiO, indicating that this source is an ultra-subdwarf M star with a radial velocity v {sub rad} ≈ –21 ± 18 km s{sup –1} relative to the Sun. Given its apparent magnitude, the distance is about 39 ± 9 pc and the tangential velocity is probably ≈330 km s{sup –1}, but a moremore » precise parallax is needed to be certain.« less
Authors:
; ;  [1] ; ; ;  [2] ; ;  [3] ; ; ;  [4] ;  [5] ;  [6] ;  [7] ;  [8]
  1. UCLA Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States)
  2. Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)
  3. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)
  4. Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)
  5. Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606-3328 (United States)
  6. STScI, Baltimore, MD 21218 (United States)
  7. Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  8. University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States)
Publication Date:
OSTI Identifier:
22339980
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 147; Journal Issue: 3; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; CALCIUM HYDRIDES; CATALOGS; COLLISIONS; DISTANCE; DWARF STARS; HYDROGEN; INFRARED SURVEYS; MASS; PHOTOMETRY; PROPER MOTION; RADIAL VELOCITY; SODIUM; SPECTRA; SUN; TITANIUM OXIDES