{"id":502601,"date":"2026-05-26T00:50:28","date_gmt":"2026-05-26T00:50:28","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/502601\/"},"modified":"2026-05-26T00:50:28","modified_gmt":"2026-05-26T00:50:28","slug":"webb-detects-methane-in-atmosphere-of-exo-saturn-toi-199b","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/502601\/","title":{"rendered":"Webb Detects Methane in Atmosphere of Exo-Saturn TOI-199b"},"content":{"rendered":"

Using spectral data from the Near-Infrared Spectrograph (NIRSpec) onboard the NASA\/ESA\/CSA James Webb Space Telescope, astronomers analyzed the atmosphere of TOI-199b, a distant Saturn-mass world that is neither frozen nor scorching hot.<\/strong><\/p>\n

\"An<\/p>\n

An artist\u2019s impression of a gas-giant exoplanet. Image credit: Sci.News.<\/p>\n

TOI-199<\/a> is a G-type star located around 330 light-years away in the constellation of Dorado.<\/p>\n

It hosts at least two massive planets: TOI-199b and TOI-199c.<\/p>\n

The inner planet orbits<\/a> its host star every 105 days, receiving 2.5 times Earth\u2019s irradiation, which corresponds to a temperature of 352 K (79 degrees Celsius, or 174 degrees Fahrenheit).<\/p>\n

Its mass (0.17 Jupiter mass) and radius (0.81 Jupiter radii) suggest a Saturn-like internal structure with a hydrogen-dominated atmosphere.<\/p>\n

\u201cTOI-199b stands out as one of the most favorable low-temperature giant planets for atmospheric characterization,\u201d said Penn State astronomer Renyu Hu and colleagues.<\/p>\n

To characterize TOI-199b\u2019s atmosphere, the astronomers used a technique called transmission spectroscopy to analyze light from the star that passes through the planet\u2019s atmosphere.<\/p>\n

\u201cWhen we compared the spectra during the transit to the baseline, we saw that the atmosphere blocked the wavelengths of starlight absorbed by methane,\u201d said Dr. Aaron Bello-Arufe, a postdoctoral researcher at NASA\u2019s Jet Propulsion Laboratory.<\/p>\n

\u201cModels for the composition of temperate, gas-giant exoplanets had predicted that they would contain methane, so it is good to get confirmation that our theories are accurate.\u201d<\/p>\n

In addition to methane, the Webb observations gave hints that the atmosphere also contained ammonia and carbon dioxide.<\/p>\n

\u201cWith additional observations of this planet, we could establish the relative abundance of these various gases in its atmosphere,\u201d Dr. Hu said.<\/p>\n

\u201cThis more complete picture of a temperate gas giant\u2019s atmosphere can then be used to improve our models and potentially better understand how planets and their atmospheres form and evolve, including for Earth.\u201d<\/p>\n

\u201cThe success of this first study of a temperate giant planet\u2019s atmosphere also gives us confidence to dedicate more resources and observation time to study other similar planets.\u201d<\/p>\n

\u201cWe can then see if this planet is unique or if there are general shared characteristics for this type of planet.\u201d<\/p>\n

The team\u2019s results<\/a> were published in the May 20 issue of the Astronomical Journal.<\/p>\n

_____<\/p>\n

Aaron Bello-Arufe et al. 2026. Methane on the Temperate Exo-Saturn TOI-199b. AJ 171, 354; doi: 10.3847\/1538-3881\/ae4fba<\/p>\n","protected":false},"excerpt":{"rendered":"Using spectral data from the Near-Infrared Spectrograph (NIRSpec) onboard the NASA\/ESA\/CSA James Webb Space Telescope, astronomers analyzed the…\n","protected":false},"author":2,"featured_media":502602,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[77],"tags":[115080,10210,17829,15441,18,6145,218352,18060,10211,19,15444,17,20707,1024,133,20991,218353,218354,218355,15450],"class_list":["post-502601","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ammonia","tag-atmosphere","tag-carbon-dioxide","tag-csa","tag-eire","tag-esa","tag-exo-saturn","tag-exoplanet","tag-gas-giant","tag-ie","tag-ir","tag-ireland","tag-methane","tag-nasa","tag-science","tag-spectrum","tag-toi-199","tag-toi-199b","tag-transmission-spectrum","tag-webb"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/116638137448966608","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/502601","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=502601"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/502601\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/502602"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=502601"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=502601"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=502601"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}