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A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion

Sing, David K. and Fortney, Jonathan J. and Nikolov, Nikolay and Wakeford, Hannah R. and Kataria, Tiffany and Evans, Thomas M. and Aigrain, Suzanne and Ballester, Gilda E. and Burrows, Adam S. and Deming, Drake and Désert, Jean-Michel and Gibson, Neale P. and Henry, Gregory W. and Huitson, Catherine M. and Knutson, Heather A. and Lecavelier des Etangs, Alain and Pont, Frederic and Showman, Adam P. and Vidal-Madjar, Alfred and Williamson, Michael H. and Wilson, Paul A. (2016) A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion. Nature, 529 (7584). pp. 59-62. ISSN 0028-0836.

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[img] Image (JPEG) (Extended Data Figure 1: ΔZ_(J − LM) versus ΔZ_(UB − LM)) - Supplemental Material
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[img] Image (JPEG) (Extended Data Figure 2: ΔZ_(UB − LM) index versus H_2O amplitude) - Supplemental Material
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[img] Image (JPEG) (Extended Data Figure 3: Stellar activity (logR′_(HK)) versus ∆Z_(UB − LM) index) - Supplemental Material
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[img] Image (JPEG) (Extended Data Figure 4: Theoretical model transmission spectra) - Supplemental Material
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[img] Image (JPEG) (Extended Data Figure 5: Brown dwarf and hot Jupiter pressure–temperature profiles and condensation curves) - Supplemental Material
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[img] Image (JPEG) (Extended Data Table 1: Summary of observations) - Supplemental Material
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Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1–1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet’s formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3–5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper ReadCube access
Sing, David K.0000-0001-6050-7645
Fortney, Jonathan J.0000-0002-9843-4354
Nikolov, Nikolay0000-0002-6500-3574
Wakeford, Hannah R.0000-0003-4328-3867
Kataria, Tiffany0000-0003-3759-9080
Evans, Thomas M.0000-0001-5442-1300
Aigrain, Suzanne0000-0003-1453-0574
Burrows, Adam S.0000-0002-3099-5024
Deming, Drake0000-0001-5727-4094
Désert, Jean-Michel0000-0002-0875-8401
Gibson, Neale P.0000-0002-9308-2353
Henry, Gregory W.0000-0003-4155-8513
Knutson, Heather A.0000-0002-0822-3095
Lecavelier des Etangs, Alain0000-0002-5637-5253
Pont, Frederic0000-0003-0076-5444
Additional Information:© 2015 Macmillan Publishers Limited. Received 19 June; accepted 1 October 2015. Published online 14 December 2015. This work is based on observations with the NASA/ESA HST, obtained at the Space Telescope Science Institute (STScI) operated by AURA, Inc. This work is also based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement number 336792. D.K.S., F.P. and N.N. acknowledge support from STFC consolidated grant ST/J0016/1. Support for this work was provided by NASA through grants under the HST-GO-12473 programme from the STScI. A.L.E., P.A.W. and A.V.M. acknowledge support from CNES and the French Agence Nationale de la Recherche (ANR), under programme ANR-12-BS05-0012 ‘Exo-Atmos’. P.A.W. and H.W. acknowledge support from the UK Science and Technology Facilities Council (STFC). G.W.H. and M.H.W. acknowledge support from NASA, NSF, Tennessee State University and the State of Tennessee through its Centers of Excellence programme. Author Contributions: D.K.S. led the data analysis for this project, with contributions from D.D., T.M.E., N.P.G., C.M.H., H.A.K., N.N., H.R.W., S.A., G.E.B. and P.A.W. J.J.F., A.S.B., A.P.S., A.L.E. and T.K. provided atmospheric models. G.W.H. and M.H.W. provided photometric stellar activity monitoring data and J.M.D. provided Spitzer data. D.K.S. wrote the manuscript along with J.J.F., H.R.W, T.K., N.N. and T.M.E. All authors discussed the results and commented on the draft. The authors declare no competing financial interests.
Funding AgencyGrant Number
European Research Council (ERC)336792
Science and Technology Facilities Council (STFC)ST/J0016/1
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Agence Nationale de la Recherche (ANR)ANR-12-BS05-0012
Tennessee State UniversityUNSPECIFIED
State of Tennessee Centers of Excellence ProgramUNSPECIFIED
Issue or Number:7584
Record Number:CaltechAUTHORS:20151221-095009065
Persistent URL:
Official Citation:A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion David K. Sing, Jonathan J. Fortney, Nikolay Nikolov, Hannah R. Wakeford, Tiffany Kataria, Thomas M. Evans, Suzanne Aigrain, Gilda E. Ballester, Adam S. Burrows, Drake Deming, Jean-Michel Désert, Neale P. Gibson, Gregory W. Henry, Catherine M. Huitson, Heather A. Knutson, Alain Lecavelier des Etangs, Frederic Pont, Adam P. Showman, Alfred Vidal-Madjar, Michael H. Williamson & Paul A. Wilson Nature 529, 59–62 (07 January 2016) doi:10.1038/nature16068
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:63103
Deposited By: Tony Diaz
Deposited On:22 Dec 2015 19:35
Last Modified:22 Apr 2020 21:41

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