Transmission spectroscopy of the hot Jupiter WASP-12b from 0.7 to 5 μm
Abstract
Since the first report of a potentially non-solar carbon-to-oxygen ratio (C/O) in its dayside atmosphere, the highly irradiated exoplanet WASP-12b has been under intense scrutiny and the subject of many follow-up observations. Additionally, the recent discovery of stellar binary companions ∼1'' from WASP-12 has obfuscated interpretation of the observational data. Here we present new ground-based multi-object transmission-spectroscopy observations of WASP-12b that we acquired over two consecutive nights in the red optical with Gemini-N/GMOS. After correcting for the influence of WASP-12's stellar companions, we find that these data rule out a cloud-free H{sub 2} atmosphere with no additional opacity sources. We detect features in the transmission spectrum that may be attributed to metal oxides (such as TiO and VO) for an O-rich atmosphere or to metal hydrides (such as TiH) for a C-rich atmosphere. We also reanalyzed NIR transit-spectroscopy observations of WASP-12b from HST/WFC3 and broadband transit photometry from Warm Spitzer. We attribute the broad spectral features in the WFC3 data to either H{sub 2}O or CH{sub 4} and HCN for an O-rich or C-rich atmosphere, respectively. The Spitzer data suggest shallower transit depths than the models predict at infrared wavelengths, albeit at low statistical significance. A multi-instrument, broad-wavelength analysis ofmore »
- Authors:
-
- Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
- Division of Geological and Planetary Sciences, California Institute of Technology, MC 170-25 1200, East California Boulevard, Pasadena, CA 91125 (United States)
- Department of Physics and Department of Astronomy, Yale University, P.O. Box 208120, New Haven, CT 06520 (United States)
- National Optical Astronomy Observatory (NOAO), Tucson, AZ 85719 (United States)
- 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)
- Publication Date:
- OSTI Identifier:
- 22340214
- Resource Type:
- Journal Article
- Journal Name:
- Astronomical Journal (New York, N.Y. Online)
- Additional Journal Information:
- Journal Volume: 147; Journal Issue: 6; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATMOSPHERES; CARBON; HYDRIDES; HYDROCYANIC ACID; HYDROGEN; IRRADIATION; JUPITER PLANET; METALS; METHANE; OPACITY; OXYGEN; PHOTOMETRY; RAYLEIGH SCATTERING; SPECTRA; SPECTROSCOPY; STARS; TITANIUM OXIDES; TRANSMISSION; VANADIUM OXIDES; WATER
Citation Formats
Stevenson, Kevin B., Bean, Jacob L., Seifahrt, Andreas, Kreidberg, Laura, Désert, Jean-Michel, Madhusudhan, Nikku, Bergmann, Marcel, and Homeier, Derek. Transmission spectroscopy of the hot Jupiter WASP-12b from 0.7 to 5 μm. United States: N. p., 2014.
Web. doi:10.1088/0004-6256/147/6/161.
Stevenson, Kevin B., Bean, Jacob L., Seifahrt, Andreas, Kreidberg, Laura, Désert, Jean-Michel, Madhusudhan, Nikku, Bergmann, Marcel, & Homeier, Derek. Transmission spectroscopy of the hot Jupiter WASP-12b from 0.7 to 5 μm. United States. https://doi.org/10.1088/0004-6256/147/6/161
Stevenson, Kevin B., Bean, Jacob L., Seifahrt, Andreas, Kreidberg, Laura, Désert, Jean-Michel, Madhusudhan, Nikku, Bergmann, Marcel, and Homeier, Derek. 2014.
"Transmission spectroscopy of the hot Jupiter WASP-12b from 0.7 to 5 μm". United States. https://doi.org/10.1088/0004-6256/147/6/161.
@article{osti_22340214,
title = {Transmission spectroscopy of the hot Jupiter WASP-12b from 0.7 to 5 μm},
author = {Stevenson, Kevin B. and Bean, Jacob L. and Seifahrt, Andreas and Kreidberg, Laura and Désert, Jean-Michel and Madhusudhan, Nikku and Bergmann, Marcel and Homeier, Derek},
abstractNote = {Since the first report of a potentially non-solar carbon-to-oxygen ratio (C/O) in its dayside atmosphere, the highly irradiated exoplanet WASP-12b has been under intense scrutiny and the subject of many follow-up observations. Additionally, the recent discovery of stellar binary companions ∼1'' from WASP-12 has obfuscated interpretation of the observational data. Here we present new ground-based multi-object transmission-spectroscopy observations of WASP-12b that we acquired over two consecutive nights in the red optical with Gemini-N/GMOS. After correcting for the influence of WASP-12's stellar companions, we find that these data rule out a cloud-free H{sub 2} atmosphere with no additional opacity sources. We detect features in the transmission spectrum that may be attributed to metal oxides (such as TiO and VO) for an O-rich atmosphere or to metal hydrides (such as TiH) for a C-rich atmosphere. We also reanalyzed NIR transit-spectroscopy observations of WASP-12b from HST/WFC3 and broadband transit photometry from Warm Spitzer. We attribute the broad spectral features in the WFC3 data to either H{sub 2}O or CH{sub 4} and HCN for an O-rich or C-rich atmosphere, respectively. The Spitzer data suggest shallower transit depths than the models predict at infrared wavelengths, albeit at low statistical significance. A multi-instrument, broad-wavelength analysis of WASP-12b suggests that the transmission spectrum is well approximated by a simple Rayleigh scattering model with a planet terminator temperature of 1870 ± 130 K. We conclude that additional high-precision data and isolated spectroscopic measurements of the companion stars are required to place definitive constraints on the composition of WASP-12b's atmosphere.},
doi = {10.1088/0004-6256/147/6/161},
url = {https://www.osti.gov/biblio/22340214},
journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 6,
volume = 147,
place = {United States},
year = {Sun Jun 01 00:00:00 EDT 2014},
month = {Sun Jun 01 00:00:00 EDT 2014}
}