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Title: ON THE METALLICITIES OF KEPLER STARS

We use 12,000 stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectroscopic survey data to show that the metallicities of Kepler field stars as given in the Kepler Input Catalog (KIC) systematically underestimate both the true metallicity and the dynamic range of the Kepler sample. Specifically, to the first order approximation, we find [Fe/H]{sub KIC} = –0.20 + 0.43[Fe/H]{sub LAMOST}, with a scatter of ∼0.25 dex, due almost entirely to errors in KIC. This relation is most secure for –0.3 < [Fe/H]{sub LAMOST} < +0.4 where we have >200 comparison stars per 0.1 dex bin and good consistency is shown between metallicities determined by LAMOST and high-resolution spectra. It remains approximately valid in a slightly broader range. When the relation is inverted, the error in true metallicity as derived from KIC is (0.25 dex)/0.43-0.6 dex. We thereby quantitatively confirm the cautionary note by Brown et al. that KIC estimates of [Fe/H] should not be used by {sup a}nyone with a particular interest in stellar metallicities{sup .} Fortunately, many more LAMOST spectroscopic metallicities will be available in the near future.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ; ;  [5] ;  [6] ; ;  [7]
  1. Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing 100871 (China)
  2. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)
  3. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
  4. Royal observatory of Belgium, Ringlaan 3, B-1180 Brussel (Belgium)
  5. Department of Astronomy, Beijing Normal University, 19 Avenue Xinjiekouwai, Beijing 100875 (China)
  6. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)
  7. University of Science and Technology of China, Hefei 230026 (China)
Publication Date:
OSTI Identifier:
22365756
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 789; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; COMPARATIVE EVALUATIONS; FIBERS; HYDROGEN; IRON; METALLICITY; RESOLUTION; STAR EVOLUTION; STARS; TELESCOPES