Produced by: Tarun Mishra
A Canadian-led international team of researchers has used the James Webb Space Telescope (JWST) to examine GJ 9827 d, an exoplanet located about 98 light-years away in the constellation Pisces.
Credit: NASA
The study, led by Caroline Piaulet-Ghorayeb from the Université de Montréal, revealed that the exoplanet's atmosphere is rich in heavier molecules, including significant amounts of water vapor, leading scientists to classify it as a potential "steam world."
GJ 9827 d is notable for having an atmosphere dominated by heavier molecules rather than hydrogen, which is typical of larger planets like gas giants. This marks the first confirmed detection of such an atmosphere on a smaller planet.
The team combined data from JWST’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) with previous Hubble Space Telescope (HST) observations. This confirmed the presence of a dense atmosphere on the exoplanet, distinguishing it from contamination by its host star.
GJ 9827 d is believed to have a dense, superheated atmosphere due to its proximity to its star. The planet’s surface temperatures reach approximately 350°C, and its atmosphere lacks distinct layers or clouds, consistent with the "steam world" theory.
Despite the presence of water vapor, GJ 9827 d is not considered habitable due to its extreme temperatures and close orbit to its star. However, the findings offer important clues in the search for habitable environments on other planets.
The discovery marks a milestone in the study of smaller exoplanets and their atmospheres, moving beyond the focus on large gas giants. It suggests that smaller, water-rich planets could be more common than previously thought.
Further JWST observations of GJ 9827 d are planned to explore the components of its atmosphere in more detail. This ongoing research could help refine our understanding of steam worlds and their potential for habitability in exoplanet systems.