|
1
|
Coulombe LP, Benneke B, Challener R, Piette AAA, Wiser LS, Mansfield M, MacDonald RJ, Beltz H, Feinstein AD, Radica M, Savel AB, Dos Santos LA, Bean JL, Parmentier V, Wong I, Rauscher E, Komacek TD, Kempton EMR, Tan X, Hammond M, Lewis NT, Line MR, Lee EKH, Shivkumar H, Crossfield IJM, Nixon MC, Rackham BV, Wakeford HR, Welbanks L, Zhang X, Batalha NM, Berta-Thompson ZK, Changeat Q, Désert JM, Espinoza N, Goyal JM, Harrington J, Knutson HA, Kreidberg L, López-Morales M, Shporer A, Sing DK, Stevenson KB, Aggarwal K, Ahrer EM, Alam MK, Bell TJ, Blecic J, Caceres C, Carter AL, Casewell SL, Crouzet N, Cubillos PE, Decin L, Fortney JJ, Gibson NP, Heng K, Henning T, Iro N, Kendrew S, Lagage PO, Leconte J, Lendl M, Lothringer JD, Mancini L, Mikal-Evans T, Molaverdikhani K, Nikolov NK, Ohno K, Palle E, Piaulet C, Redfield S, Roy PA, Tsai SM, Venot O, Wheatley PJ. A broadband thermal emission spectrum of the ultra-hot Jupiter WASP-18b. Nature 2023; 620:292-298. [PMID: 37257843 PMCID: PMC10412449 DOI: 10.1038/s41586-023-06230-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/16/2023] [Indexed: 06/02/2023]
Abstract
Close-in giant exoplanets with temperatures greater than 2,000 K ('ultra-hot Jupiters') have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from the Hubble Space Telescope (HST) and Spitzer Space Telescope1-3. However, previous studies have yielded inconsistent results because the small sizes of the spectral features and the limited information content of the data resulted in high sensitivity to the varying assumptions made in the treatment of instrument systematics and the atmospheric retrieval analysis3-12. Here we present a dayside thermal emission spectrum of the ultra-hot Jupiter WASP-18b obtained with the NIRISS13 instrument on the JWST. The data span 0.85 to 2.85 μm in wavelength at an average resolving power of 400 and exhibit minimal systematics. The spectrum shows three water emission features (at >6σ confidence) and evidence for optical opacity, possibly attributable to H-, TiO and VO (combined significance of 3.8σ). Models that fit the data require a thermal inversion, molecular dissociation as predicted by chemical equilibrium, a solar heavy-element abundance ('metallicity', [Formula: see text] times solar) and a carbon-to-oxygen (C/O) ratio less than unity. The data also yield a dayside brightness temperature map, which shows a peak in temperature near the substellar point that decreases steeply and symmetrically with longitude towards the terminators.
Collapse
Affiliation(s)
- Louis-Philippe Coulombe
- Department of Physics, Université de Montréal, Montréal, Quebec, Canada.
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montréal, Quebec, Canada.
| | - Björn Benneke
- Department of Physics, Université de Montréal, Montréal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montréal, Quebec, Canada
| | - Ryan Challener
- Department of Astronomy, University of Michigan, Ann Arbor, MI, USA
| | - Anjali A A Piette
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA
| | - Lindsey S Wiser
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | | | - Ryan J MacDonald
- Department of Astronomy, University of Michigan, Ann Arbor, MI, USA
- Department of Astronomy, Cornell University, Ithaca, NY, USA
- Carl Sagan Institute, Cornell University, Ithaca, NY, USA
| | - Hayley Beltz
- Department of Astronomy, University of Michigan, Ann Arbor, MI, USA
| | - Adina D Feinstein
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA
| | - Michael Radica
- Department of Physics, Université de Montréal, Montréal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montréal, Quebec, Canada
| | - Arjun B Savel
- Department of Astronomy, University of Maryland, College Park, MD, USA
- Center for Computational Astrophysics, Flatiron Institute, New York, NY, USA
| | | | - Jacob L Bean
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA
| | - Vivien Parmentier
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - Ian Wong
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Emily Rauscher
- Department of Astronomy, University of Michigan, Ann Arbor, MI, USA
| | | | - Eliza M-R Kempton
- Department of Astronomy, University of Maryland, College Park, MD, USA
| | - Xianyu Tan
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, UK
| | - Mark Hammond
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, UK
| | - Neil T Lewis
- Department of Mathematics and Statistics, Faculty of Environment, Science and Economy, University of Exeter, Exeter, UK
| | - Michael R Line
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Elspeth K H Lee
- Center for Space and Habitability, University of Bern, Bern, Switzerland
| | - Hinna Shivkumar
- Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, The Netherlands
| | - Ian J M Crossfield
- Department of Physics & Astronomy, University of Kansas, Lawrence, KS, USA
| | - Matthew C Nixon
- Department of Astronomy, University of Maryland, College Park, MD, USA
| | - Benjamin V Rackham
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Luis Welbanks
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Xi Zhang
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Natalie M Batalha
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Zachory K Berta-Thompson
- Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, Boulder, CO, USA
| | - Quentin Changeat
- European Space Agency, Space Telescope Science Institute, Baltimore, MD, USA
- Department of Physics and Astronomy, University College London, London, UK
| | - Jean-Michel Désert
- Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Jayesh M Goyal
- School of Earth and Planetary Sciences (SEPS), National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Jatni, India
| | - Joseph Harrington
- Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL, USA
- Florida Space Institute, University of Central Florida, Orlando, FL, USA
| | - Heather A Knutson
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | | | | | - Avi Shporer
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - David K Sing
- Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA
- Department of Physics & Astronomy, Johns Hopkins University, Baltimore, MD, USA
| | | | | | - Eva-Maria Ahrer
- Centre for Exoplanets and Habitability, University of Warwick, Coventry, UK
- Department of Physics, University of Warwick, Coventry, UK
| | - Munazza K Alam
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA
| | - Taylor J Bell
- Bay Area Environmental Research Institute, NASA Ames Research Center, Moffett Field, CA, USA
| | - Jasmina Blecic
- Department of Physics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
- Center for Astro, Particle, and Planetary Physics (CAP3), New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Claudio Caceres
- Instituto de Astrofisica, Universidad Andrés Bello, Santiago, Chile
- Núcleo Milenio de Formación Planetaria (NPF), Valparaíso, Chile
- Centro de Astrofisica y Tecnologias Afines (CATA), Santiago, Chile
| | - Aarynn L Carter
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Sarah L Casewell
- School of Physics and Astronomy, University of Leicester, Leicester, UK
| | - Nicolas Crouzet
- Leiden Observatory, University of Leiden, Leiden, The Netherlands
| | - Patricio E Cubillos
- INAF - Osservatorio Astrofisico di Torino, Pino Torinese, Italy
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - Leen Decin
- Institute of Astronomy, Department of Physics and Astronomy, KU Leuven, Leuven, Belgium
| | - Jonathan J Fortney
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Neale P Gibson
- School of Physics, Trinity College Dublin, Dublin, Ireland
| | - Kevin Heng
- Department of Physics, University of Warwick, Coventry, UK
- Universitäts-Sternwarte München, Ludwig-Maximilians-Universität München, München, Germany
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | | | - Nicolas Iro
- Institute of Planetary Research (PF), German Aerospace Center (DLR), Berlin, Germany
| | - Sarah Kendrew
- European Space Agency, Space Telescope Science Institute, Baltimore, MD, USA
| | - Pierre-Olivier Lagage
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | - Jérémy Leconte
- Laboratoire d'Astrophysique de Bordeaux, Université de Bordeaux, Pessac, France
| | - Monika Lendl
- Département d'Astronomie, Université de Genève, Sauverny, Switzerland
| | | | - Luigi Mancini
- Max Planck Institute for Astronomy, Heidelberg, Germany
- INAF - Osservatorio Astrofisico di Torino, Pino Torinese, Italy
- Department of Physics, University of Rome "Tor Vergata", Rome, Italy
| | | | - Karan Molaverdikhani
- Max Planck Institute for Astronomy, Heidelberg, Germany
- Universitäts-Sternwarte München, Ludwig-Maximilians-Universität München, München, Germany
- Exzellenzcluster Origins, Garching, Germany
| | | | - Kazumasa Ohno
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Enric Palle
- Instituto de Astrofísica de Canarias (IAC), Tenerife, Spain
| | - Caroline Piaulet
- Department of Physics, Université de Montréal, Montréal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montréal, Quebec, Canada
| | - Seth Redfield
- Astronomy Department, Van Vleck Observatory, Wesleyan University, Middletown, CT, USA
| | - Pierre-Alexis Roy
- Department of Physics, Université de Montréal, Montréal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montréal, Quebec, Canada
| | - Shang-Min Tsai
- Department of Earth and Planetary Sciences, University of California, Riverside, Riverside, CA, USA
| | - Olivia Venot
- Université Paris Cité and Université Paris-Est Creteil, CNRS, LISA, Paris, France
| | - Peter J Wheatley
- Centre for Exoplanets and Habitability, University of Warwick, Coventry, UK
- Department of Physics, University of Warwick, Coventry, UK
| |
Collapse
|