For the first time, astronomers have found unambiguous evidence of carbon dioxide in the atmosphere of an exoplanet (a planet outside our solar system).
[...] Natalie Batalha, professor of astronomy and astrophysics at UC Santa Cruz, leads the team of astronomers that made the detection, using JWST to observe a Saturn-mass planet called WASP-39b which orbits very close to a sun-like star about 700 light-years from Earth.
"Previous observations of this planet with Hubble and Spitzer had given us tantalizing hints that carbon dioxide could be present," Batalha said. "The data from JWST showed an unequivocal carbon dioxide feature that was so prominent it was practically shouting at us."
Carbon dioxide is an important component of the atmospheres of planets in our solar system, found on rocky planets like Mars and Venus as well as gas giants like Jupiter and Saturn. For exoplanet researchers, it is important both as a gas they are likely to be able to detect on small rocky planets and as an indicator of the overall abundance of heavy elements in the atmospheres of giant planets.
"Carbon dioxide is actually a very sensitive measuring stick—the best one we have—for heavy elements in giant planet atmospheres, so the fact that we can see it so clearly is really great," said coauthor Jonathan Fortney, professor of astronomy and astrophysics at UCSC and director of the Other Worlds Laboratory.
[...] "The ability to determine the amount of heavy elements in a planet is critical to understanding how it formed, and we'll be able to use this carbon dioxide measuring stick for a whole bunch of exoplanets to build up a comprehensive understanding of giant planet composition," he said.
[...] Using the Near Infrared Spectrograph (NIRSpec) on JWST, the team obtained a high-resolution "transmission spectrum" showing the light transmitted through WASP-39b's atmosphere separated into its component wavelengths. Batalha said the data yielded "exquisite light curves" and showed that the NIRSpec instrument is exceeding expectations for transmission spectroscopy. This bodes well for observations of small rocky planets, which are expected to have carbon dioxide in their atmospheres (when they have atmospheres) but won't give as strong a signal as a giant planet like WASP-39b.
"This detection will serve as a useful benchmark of what we can do to detect carbon dioxide on terrestrial planets going forward," Batalha said. "It's the most likely atmospheric gas we'll detect with JWST in terrestrial-size exoplanet atmospheres."
[...] When the first data from JWST were released in July, the UCSC exoplanet researchers were hosting 45 visiting astronomers for the Other Worlds Laboratory's annual Exoplanet Summer Program. "We were all huddled around the laptop getting our first look at the spectrum and marveling at it," Batalha said. "It's a tremendous, almost euphoric feeling, seeing something for the first time that no other human has seen before—that's what science is all about."
(Score: 3, Informative) by takyon on Saturday August 27 2022, @12:36PM
https://www.stsci.edu/files/live/sites/www/files/home/jwst/science-execution/observing-schedules/_documents/2224108f01_report_20220829.txt [stsci.edu]
They are doing spectroscopy of Eris twice next week.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]