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Title: DISCOVERY OF FOUR HIGH PROPER MOTION L DWARFS, INCLUDING A 10 pc L DWARF AT THE L/T TRANSITION {sup ,}

We discover four high proper motion L dwarfs by comparing the Wide-field Infrared Survey Explorer (WISE) to the Two Micron All Sky Survey. WISE J140533.32+835030.5 is an L dwarf at the L/T transition with a proper motion of 0.85 ± 0.''02 yr{sup –1}, previously overlooked due to its proximity to a bright star (V ≈ 12 mag). From optical spectroscopy we find a spectral type of L8, and from moderate-resolution J band spectroscopy we find a near-infrared spectral type of L9. We find WISE J140533.32+835030.5 to have a distance of 9.7 ± 1.7 pc, bringing the number of L dwarfs at the L/T transition within 10 pc from six to seven. WISE J040137.21+284951.7, WISE J040418.01+412735.6, and WISE J062442.37+662625.6 are all early L dwarfs within 25 pc, and were classified using optical and low-resolution near-infrared spectra. WISE J040418.01+412735.6 is an L2 pec (red) dwarf, a member of the class of unusually red L dwarfs. We use follow-up optical and low-resolution near-infrared spectroscopy to classify a previously discovered fifth object WISEP J060738.65+242953.4 as an (L8 Opt/L9 NIR), confirming it as an L dwarf at the L/T transition within 10 pc. WISEP J060738.65+242953.4 shows tentative CH{sub 4} in the H band, possibly themore » result of unresolved binarity with an early T dwarf, a scenario not supported by binary spectral template fitting. If WISEP J060738.65+242953.4 is a single object, it represents the earliest onset of CH{sub 4} in the H band of an L/T transition dwarf in the SpeX Library. As very late L dwarfs within 10 pc, WISE J140533.32+835030.5 and WISEP J060738.65+242953.4 will play a vital role in resolving outstanding issues at the L/T transition.« less
Authors:
;  [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ;  [6]
  1. Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)
  2. US Naval Observatory, Flagstaff Station, 10391 West Naval Observatory Road, Flagstaff, AZ 86001 (United States)
  3. Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States)
  4. Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)
  5. Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08544 (United States)
  6. Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)
Publication Date:
OSTI Identifier:
22270810
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 776; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; ASTRONOMY; ASTROPHYSICS; COMPARATIVE EVALUATIONS; DWARF STARS; INFRARED SPECTRA; METHANE; NEAR INFRARED RADIATION; PROPER MOTION; RESOLUTION