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Title: Updated Spitzer emission spectroscopy of bright transiting hot Jupiter HD 189733b

We analyze all existing secondary eclipse time series spectroscopy of hot Jupiter HD 189733b acquired with the now defunct Spitzer/Infrared Spectrograph (IRS) instrument. We describe the novel approaches we develop to remove the systematic effects and extract accurate secondary eclipse depths as a function of wavelength in order to construct the emission spectrum of the exoplanet. We compare our results with a previous study by Grillmair et al. that did not examine all data sets available to us. We are able to confirm the detection of a water feature near 6 μm claimed by Grillmair et al. We compare the planetary emission spectrum to three model families—based on isothermal atmosphere, gray atmosphere, and two realizations of the complex radiative transfer model by Burrows et al., adopted in Grillmair et al.'s study. While we are able to reject the simple isothermal and gray models based on the data at the 97% level just from the IRS data, these rejections hinge on eclipses measured within a relatively narrow wavelength range, between 5.5 and 7 μm. This underscores the need for observational studies with broad wavelength coverage and high spectral resolution, in order to obtain robust information on exoplanet atmospheres.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)
  2. Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States)
  3. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
  4. Spitzer Science Center, California Institute of Technology, Mail Stop 220-6, Pasadena, CA 91125 (United States)
Publication Date:
OSTI Identifier:
22370143
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 796; 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; ASTROPHYSICS; ATMOSPHERES; COMPARATIVE EVALUATIONS; DETECTION; ECLIPSE; EMISSION SPECTRA; EMISSION SPECTROSCOPY; PLANETS; RADIANT HEAT TRANSFER; RESOLUTION; WATER; WAVELENGTHS