The Astronomical Journal (Jan 2025)
JWST-TST DREAMS: A Supersolar Metallicity in WASP-17 b’s Dayside Atmosphere from NIRISS SOSS Eclipse Spectroscopy
- Amélie Gressier,
- Ryan J. MacDonald,
- Néstor Espinoza,
- Hannah R. Wakeford,
- Nikole K. Lewis,
- Jayesh Goyal,
- Dana R. Louie,
- Michael Radica,
- Natasha E. Batalha,
- Douglas Long,
- Erin M. May,
- Elijah Mullens,
- Sara Seager,
- Kevin B. Stevenson,
- Jeff A. Valenti,
- Lili Alderson,
- Natalie H. Allen,
- Caleb I. Cañas,
- Ryan C. Challener,
- Knicole Colón,
- Ana Glidden,
- David Grant,
- Jingcheng Huang,
- Zifan Lin,
- Daniel Valentine,
- C. Matt Mountain,
- Laurent Pueyo,
- Marshall D. Perrin,
- Roeland P. van der Marel
Affiliations
- Amélie Gressier
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Ryan J. MacDonald
- ORCiD
- Department of Astronomy, University of Michigan , 1085 S. University Avenue, Ann Arbor, MI 48109, USA
- Néstor Espinoza
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]; William H. Miller III Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA
- Hannah R. Wakeford
- ORCiD
- University of Bristol , HH Wills Physics Laboratory, Tyndall Avenue, Bristol, UK
- Nikole K. Lewis
- ORCiD
- Department of Astronomy and Carl Sagan Institute, Cornell University , 122 Sciences Drive, Ithaca, NY 14853, USA
- Jayesh Goyal
- ORCiD
- School of Earth and Planetary Sciences (SEPS), National Institute of Science Education and Research (NISER) , HBNI, Odisha, India
- Dana R. Louie
- ORCiD
- Catholic University of America , Department of Physics, Washington, DC 20064, USA; Exoplanets and Stellar Astrophysics Laboratory (Code 667), NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA; Center for Research and Exploration in Space Science and Technology II , NASA/GSFC, Greenbelt, MD 20771, USA
- Michael Radica
- ORCiD
- Institut Trottier de recherche sur les exoplanètes and Département de Physique, Université de Montréal , 1375 Avenue Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada
- Natasha E. Batalha
- ORCiD
- NASA Ames Research Center , Moffett Field, CA 94035, USA
- Douglas Long
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Erin M. May
- ORCiD
- Johns Hopkins APL , 11100 Johns Hopkins Road, Laurel, MD 20723, USA
- Elijah Mullens
- ORCiD
- Department of Astronomy and Carl Sagan Institute, Cornell University , 122 Sciences Drive, Ithaca, NY 14853, USA
- Sara Seager
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139, USA; Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA; Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Kevin B. Stevenson
- ORCiD
- Johns Hopkins APL , 11100 Johns Hopkins Road, Laurel, MD 20723, USA
- Jeff A. Valenti
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Lili Alderson
- ORCiD
- University of Bristol , HH Wills Physics Laboratory, Tyndall Avenue, Bristol, UK
- Natalie H. Allen
- ORCiD
- William H. Miller III Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA
- Caleb I. Cañas
- ORCiD
- NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA
- Ryan C. Challener
- ORCiD
- Department of Astronomy and Carl Sagan Institute, Cornell University , 122 Sciences Drive, Ithaca, NY 14853, USA
- Knicole Colón
- ORCiD
- NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA
- Ana Glidden
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- David Grant
- ORCiD
- University of Bristol , HH Wills Physics Laboratory, Tyndall Avenue, Bristol, UK
- Jingcheng Huang
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- Zifan Lin
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- Daniel Valentine
- ORCiD
- University of Bristol , HH Wills Physics Laboratory, Tyndall Avenue, Bristol, UK
- C. Matt Mountain
- Association of Universities for Research in Astronomy , 1331 Pennsylvania Avenue NW Suite 1475, Washington, DC 20004, USA
- Laurent Pueyo
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Marshall D. Perrin
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Roeland P. van der Marel
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]; William H. Miller III Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA
- DOI
- https://doi.org/10.3847/1538-3881/ad97bf
- Journal volume & issue
-
Vol. 169,
no. 2
p. 57
Abstract
We present the first emission spectrum of the hot Jupiter WASP-17 b using one eclipse observation from the JWST Near Infrared Imager and Slitless Spectrograph (NIRISS) Single Object Slitless Spectroscopy (SOSS) mode. Covering a wavelength range of 0.6–2.8 μ m, our retrieval analysis reveals a strong detection of H _2 O in WASP-17 b’s dayside atmosphere (6.4 σ ). Our retrievals consistently favor a supersolar dayside H _2 O abundance and a noninverted temperature–pressure profile over a large pressure range. Additionally, our examination of the brightness temperature reveals excess emission below 1 μ m, suggesting the possibility of a high internal temperature (600–700 K) and/or contributions from reflected light. We highlight that JWST emission spectroscopy retrieval results can be sensitive to whether negative eclipse depths are allowed at optical wavelengths during light-curve fitting. Our findings deepen our understanding of WASP-17 b’s atmospheric composition while also highlighting the sensitivity of our results to pressure–temperature profile parameterizations. This work is part of a series of studies by our JWST Telescope Scientist Team (TST), in which we will use Guaranteed Time Observations to perform Deep Reconnaissance of Exoplanet Atmospheres through Multi-instrument Spectroscopy (DREAMS).
Keywords
- Exoplanet atmospheres
- Exoplanet atmospheric composition
- Transmission spectroscopy
- Hot Jupiters
- Astronomy data reduction
