Webb image archive
Hot Gas Giant Exoplanet WASP-39 b Transmission Spectrum (NIRSpec)
This transmission spectrum, captured using Webb’s NIRSpec (Near-Infrared Spectrograph) PRISM bright object-time series mode, shows the amounts of near-infrared starlight blocked ...
- Date
- Jul 15, 2024
- Observatory
- James Webb Space Telescope
- Credit
- NASA / ESA / CSA / STScI
- Archive ID
- 01J2F17Q0XNKCR57BZGA80TSJY
This transmission spectrum, captured using Webb’s NIRSpec (Near-Infrared Spectrograph) PRISM bright object-time series mode, shows the amounts of near-infrared starlight blocked by the atmosphere of hot gas giant exoplanet WASP-39 b. The spectrum shows clear evidence for water and carbon dioxide, and a variation in temperature between the morning and evening on the exoplanet.
New analysis of the transmission spectrum of WASP-39 b builds two different spectra from the stationary day/night boundary on the exoplanet, essentially splitting this terminator region into two semicircles, one from the evening, and the other from the morning. Data reveals the evening as significantly hotter, a searing 1,450 degrees Fahrenheit (800 degrees Celsius), and the morning a relatively cooler 1,150 degrees Fahrenheit (600 degrees Celsius).
The blue and yellow lines are a best-fit model that takes into account the data, the known properties of WASP-39 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere.
Credits
Illustration
NASA, ESA, CSA, Ralf Crawford (STScI)