skip to main content

Title: On the detection of molecules in the atmosphere of HD 189733b using HST NICMOS transmission spectroscopy

The Hubble Space Telescope/NICMOS transmission spectrum measurements of HD 189733b that suggest the detection of methane (CH{sub 4}) in an exoplanet atmosphere have been a source of significant controversy. With what is probably the best analyzed exoplanet spectroscopy data set to date, different teams, using different methods, have claimed evidence both contradicting and supporting the original findings. Here, we report results from a uniform spectral retrieval analysis of the three independent published spectra together with null hypothesis testing. Based on Bayesian model comparison, we find that two of the three spectra show strong evidence (≥3.6σ) for the detection of molecular features mainly due to water and methane while the third is consistent with a weak molecular detection at the 2.2σ level. We interpret the agreement in the spectral modulation established by previous authors and the atmospheric retrieval results presented here, as a confirmation of the original detection of molecular absorbers in the atmosphere of HD 189733b.
Authors:
;  [1] ;  [2]
  1. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)
  2. Department of Astronomy and Astrophysics, University of California-Santa Cruz, Santa Cruz, CA 95064 (United States)
Publication Date:
OSTI Identifier:
22357254
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 784; 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; DATA ANALYSIS; DETECTION; HYPOTHESIS; METHANE; MODULATION; MOLECULES; PLANETS; RADIANT HEAT TRANSFER; SATELLITE ATMOSPHERES; SATELLITES; SPACE; SPECTRA; SPECTROSCOPY; TELESCOPES; TRANSMISSION; WATER