hot Jupiter<\/a>.\u201d<\/p>\nThe team\u2019s effort demonstrates a technique called 3D eclipse mapping, or spectroscopic eclipse mapping. The effort builds on a 2D model that members of the same team published in 2023, which demonstrated eclipse mapping\u2019s potential to leverage highly sensitive observations by the JWST, Earth\u2019s most powerful space telescope. Operated by NASA, the JWST is also supported by the European Space Agency and the Canadian Space Agency.<\/p>\n
\u201cEclipse mapping allows us to image exoplanets that we can\u2019t see directly, because their host stars are too bright,\u201d says Challener, a postdoctoral associate at Cornell. \u201cWith this telescope and this new technique, we can start to understand exoplanets along the same lines as our solar system neighbors.\u201d<\/p>\n
Similar to how Earth-based telescopes enabled astronomers to start characterizing Jupiter\u2019s Great Red Spot long ago, JWST will now enable scientists to start characterizing more exoplanet atmospheres with this technique, the team says.<\/p>\n
Detecting exoplanets is a challenge to begin with. Light from their host stars can overwhelm what\u2019s emitted by the planets. In terms of brightness, exoplanets are typically less than 0.1% as bright as their stars.<\/p>\n
\u201cThe analogy is a firefly in front of a lighthouse,\u201d Rauscher says. \u201cBut we know when the planet is in front of and when it\u2019s behind the star. We can actually measure that tiny little dip that had been light coming from the planet.\u201d<\/p>\n
JWST can precisely measure how that light is lost as the planet moves behind the star. This enables scientists to link minute changes in light to specific regions to produce a brightness map across a spectrum of different light wavelengths, or colors. That spectroscopic information can be converted to temperatures in three dimensions: latitude, longitude, and altitude.<\/p>\n
WASP-18b, which has roughly the mass of 10 Jupiters, orbits in just 23 hours and has temperatures approaching 5,000 degrees Fahrenheit. That provided JWST with a relatively strong signal, making it a good test case for the new mapping technique.<\/p>\n
The new view of the exoplanet confirmed spectroscopically distinct regions in WASP-18b\u2019s visible \u201cdayside,\u201d the side always facing the star due to its tidally locked orbit. The planet features a circular \u201chotspot\u201d where the most direct starlight lands, and where winds appear too weak to redistribute the heat. Surrounding the hotspot is a colder ring nearer the planet\u2019s outer visible edges, or limbs. Notably, Challener says, measurements showed lower levels of water vapor in the hotspot than WASP-18b\u2019s average.<\/p>\n
\u201cWe think that\u2019s evidence that the planet is so hot in this region that it\u2019s starting to break down the water,\u201d Challener says. \u201cThat had been predicted by theory, but it\u2019s really exciting to actually see this with real observations.\u201d<\/p>\n
Additional JWST observations could help improve the first 3D eclipse map\u2019s spatial resolution, the team says. And the technique can already help map the 3D temperature variation of other hot Jupiters, which account for hundreds of the more than 6,000 exoplanets confirmed to date.<\/p>\n
\u201cOne of the really cool things about exoplanets is that most of the planets we found are completely unlike the ones in our solar system,\u201d Rauscher says.<\/p>\n
\u201cAnd so it\u2019s a lot of fun to try and figure out how we take what we understand, more or less, in our solar system and stretch it to these very different situations.\u201d<\/p>\n
The team included about three dozen researchers from more than 20 institutions worldwide. The research was supported by JWST\u2019s Transiting Exoplanet Community Early Release Science Program.<\/p>\n
Source: University of Michigan<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Share this Article You are free to share this article under the Attribution 4.0 International license. Researchers have…\n","protected":false},"author":2,"featured_media":138082,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[9411,61,60,82,247],"class_list":["post-138081","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-exoplanets","tag-ie","tag-ireland","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/138081","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=138081"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/138081\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/138082"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=138081"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=138081"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=138081"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}