Abstract
The Hubble Space Telescope/NICMOS transmission spectrum measurements of HD 189733b that suggest the detection of methane (CH4) 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.
Original language | English (US) |
---|---|
Article number | 133 |
Journal | Astrophysical Journal |
Volume | 784 |
Issue number | 2 |
DOIs | |
State | Published - Apr 1 2014 |
Externally published | Yes |
Keywords
- planetary systems
- planets and satellites: atmospheres
- planets and satellites: individual (HD 189733b)
- radiative transfer
- words: methods: data analysis
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science