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Title: A PRECISE WATER ABUNDANCE MEASUREMENT FOR THE HOT JUPITER WASP-43b

Journal Article · · Astrophysical Journal Letters
; ;  [1];  [2]; ;  [3];  [4]; ;  [5];  [6];  [7];  [8];  [9]; ;  [10];  [11]
  1. Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
  2. CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)
  3. Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)
  4. Institute for Astronomy, University of Cambridge, Cambridge CB3 OHA (United Kingdom)
  5. Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tuscon, AZ 85721 (United States)
  6. Department of Astronomy, Harvard University, Cambridge, MA 02138 (United States)
  7. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
  8. Department of Physics, Massachussetts Institute of Technology, Cambridge, MA 02139 (United States)
  9. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
  10. Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 (United States)
  11. Centre de Recherche Astrophysique de Lyon, UMR 5574, CNRS, Université de Lyon, École Normale Supérieure de Lyon, 46 Allée d'Italie, F-69364 Lyon Cedex 07 (France)

The water abundance in a planetary atmosphere provides a key constraint on the planet's primordial origins because water ice is expected to play an important role in the core accretion model of planet formation. However, the water content of the solar system giant planets is not well known because water is sequestered in clouds deep in their atmospheres. By contrast, short-period exoplanets have such high temperatures that their atmospheres have water in the gas phase, making it possible to measure the water abundance for these objects. We present a precise determination of the water abundance in the atmosphere of the 2 M {sub Jup} short-period exoplanet WASP-43b based on thermal emission and transmission spectroscopy measurements obtained with the Hubble Space Telescope. We find the water content is consistent with the value expected in a solar composition gas at planetary temperatures (0.4-3.5 × solar at 1σ confidence). The metallicity of WASP-43b's atmosphere suggested by this result extends the trend observed in the solar system of lower metal enrichment for higher planet masses.

OSTI ID:
22364965
Journal Information:
Astrophysical Journal Letters, Vol. 793, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English