Jonathan J Fortney

About

Jonathan J Fortney is a Professor and Chair in the Department of Astronomy & Astrophysics within the Division of Physical & Biological Sciences. His expertise encompasses astrophysics and astronomy, with a focus on planetary atmospheres, planetary interiors, and exoplanets. Fortney's research aims to understand different kinds of planets as classes of astrophysical objects by characterizing their composition and evolution over time. He primarily functions as a modeler and theorist, working closely with observers to study the atmosphere, interior, and thermal evolution of planets both within the solar system and around other stars, at various distances from their parent stars. His work involves studying planets at different ages, from young to old, and across different environments, to better understand their physical properties and developmental processes.

Research topics

• Physics
• Astronomy
• Astrobiology
• Astrophysics
• Meteorology
• Chemistry
• Biology
• Environmental science
• Geology
• Computer Science

Selected publications

• Photochemically produced SO2 in the atmosphere of WASP-39b

  Nature · 2023 · 236 citations

  also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations.

  DOI

• Early Release Science of the exoplanet WASP-39b with JWST NIRISS

  Nature · 2023 · 210 citations

  . Here we present the transmission spectrum of WASP-39b obtained using the Single-Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST. This spectrum spans 0.6-2.8 μm in wavelength and shows several water-absorption bands, the potassium resonance doublet and signatures of clouds. The precision and broad wavelength coverage of NIRISS/SOSS allows us to break model degeneracies between cloud properties and the atmospheric com…

  DOI

• Identification of carbon dioxide in an exoplanet atmosphere

  Nature · 2022 · 184 citations

  , but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0 micrometres that is not reproduced by these models.

  DOI

• Early Release Science of the exoplanet WASP-39b with JWST NIRCam

  Nature · 2023 · 180 citations

  ).

  DOI

• The JWST Early-release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 μm Spectrum of the Planetary-mass Companion VHS 1256–1257 b

  The Astrophysical Journal Letters · 2023 · 160 citations

  Abstract We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a <20 M Jup widely separated (∼8″, a = 150 au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799c, d, and e. As an L-to-T transition object, VHS 1256 b exists along the region of the color–magnitude diagram where substellar atmospheres transition from cloudy to clear. We observed VHS 1256 b with JWST's NIRSpec…

  PublisherOA PDFDOI

Recent grants

• Towards a Comprehensive Understanding of Brown Dwarf Atmospheres

  NSF · $245k · 2015–2018

• Evolutionary Models of Young Jupiters and Hot Jupiters

  NSF · $165k · 2008–2010

• Collaborative Research: Characterizing Cloudy Exoplanet Atmospheres

  NSF · $335k · 2013–2016

Frequent coauthors

• Mark S. Marley

  University of Arizona

  304 shared

• Caroline Morley

  211 shared

• Jean-Michel Désert

  211 shared

• Kevin B. Stevenson

  Johns Hopkins University Applied Physics Laboratory

  178 shared

• Heather A. Knutson

  California Institute of Technology

  157 shared

• Nikole K. Lewis

  157 shared

• Michael R. Line

  151 shared

• Adam P. Showman

  144 shared

Labs

• Other Worlds LaboratoryPI

Education

• Ph.D., Astronomy

  California Institute of Technology

  2003

• M.S., Astronomy

  California Institute of Technology

  1999

• B.S., Physics

  Harvard University

  1997

Similar researchers at University of California, Santa Cruz

• Jason Xavier Prochaskah-125
• Piero Madauh-108
• Kevin A Bundyh-92