{"id":106305,"date":"2025-10-29T02:48:11","date_gmt":"2025-10-29T02:48:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/106305\/"},"modified":"2025-10-29T02:48:11","modified_gmt":"2025-10-29T02:48:11","slug":"astronomers-create-3d-temperature-map-of-hot-jupiter-wasp-18b","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/106305\/","title":{"rendered":"Astronomers Create 3D Temperature Map of Hot-Jupiter WASP-18b"},"content":{"rendered":"

The new map of WASP-18b<\/a>, a hot-Jupiter exoplanet located approximately 325 light-years from Earth, reveals an atmosphere with distinct temperature zones \u2014 one so scorching that it breaks down water vapor.<\/p>\n

\"The<\/p>\n

The hot-Jupiter WASP-18b. Image credit: NASA\u2019s Goddard Space Flight Center.<\/p>\n

The map of WASP-18b is the first applying a technique called 3D eclipse mapping, or spectroscopic eclipse mapping.<\/p>\n

This study builds on a 2D model<\/a> that members of the same team published in 2023, which demonstrated eclipse mapping\u2019s potential to tap into highly sensitive observations by the NASA\/ESA\/CSA James Webb Space Telescope.<\/p>\n

\u201cThis technique is really the only one that can probe all three dimensions at once: latitude, longitude and altitude,\u201d said Dr. Megan Weiner Mansfield, an astronomer at the University of Maryland and Arizona State University.<\/p>\n

\u201cThis gives us a higher level of detail than we\u2019ve ever had to study these celestial bodies.\u201d<\/p>\n

Using this technique, the astronomer can now begin mapping atmospheric variations for many similar types of exoplanets observable by Webb, just as Earth-based telescopes long ago observed Jupiter\u2019s Great Red Spot and banded cloud structure.<\/p>\n

\u201cEclipse mapping allows us to image exoplanets that we can\u2019t see directly, because their host stars are too bright,\u201d said Dr. Ryan Challener, an astronomer at Cornell University and the University of Maryland.<\/p>\n

\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

Detecting exoplanets at all is difficult \u2014 they typically emit much less than 1% of a host star\u2019s brightness.<\/p>\n

Eclipse mapping requires measuring small fractions of that total as a planet circles behind its star, obscuring and revealing parts of it along the way.<\/p>\n

Scientists can link minute changes in light to specific regions to produce a brightness map that, when done in multiple colors, can be converted to temperatures in three dimensions: latitude, longitude and altitude.<\/p>\n

\u201cYou\u2019re looking for changes in tiny portions of the planet as they disappear and reappear into view, so it\u2019s extraordinarily challenging,\u201d Dr. Challener said.<\/p>\n

WASP-18b, which has roughly the mass of 10 Jupiters, orbits in just 23 hours and has temperatures approaching 2,760 degrees Celsius (5,000 degrees Fahrenheit) \u2014 provided a relatively strong signal, making it a good test case for the new mapping technique.<\/p>\n

While the earlier 2D map utilized a single light wavelength, or color, the 3D map re-analyzed the same observations from Webb\u2019s Near-Infrared Imager and Slitless Spectrograph (NIRISS) instrument in many wavelengths.<\/p>\n

\u201cEach color corresponded to different temperatures and altitudes within WASP-18b\u2019s gaseous atmosphere that could be pieced together to create the 3D map,\u201d Dr. Challener said.<\/p>\n

\u201cIf you build a map at a wavelength that water absorbs, you\u2019ll see the water deck in the atmosphere, whereas a wavelength that water does not absorb will probe deeper.\u201d<\/p>\n

\u201cIf you put those together, you can get a 3D map of the temperatures in this atmosphere.\u201d<\/p>\n

The new view confirmed spectroscopically distinct regions \u2014 differing in temperature and possibly in chemical composition \u2014 in WASP-18b\u2019s visible dayside, the side always facing the star due to its tidally locked orbit.<\/p>\n

The planet features a circular \u2018hotspot\u2019 where the most direct starlight lands, and where winds apparently aren\u2019t strong enough to redistribute the heat.<\/p>\n

Surrounding the hotspot is a colder \u2018ring\u2019 nearer the planet\u2019s outer visible edges, or limbs.<\/p>\n

Notably, the 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 Dr. Challener said.<\/p>\n

\u201cThat had been predicted by theory, but it\u2019s really exciting to actually see this with real observations.\u201d<\/p>\n

\u201cAdditional Webb observations could help improve the first 3D eclipse map\u2019s spatial resolution.\u201d<\/p>\n

\u201cAlready the technique can help illuminate the temperature maps of other hot Jupiters, which make up hundreds of the more than 6,000 exoplanets confirmed to date.\u201d<\/p>\n

\u201cIt\u2019s very exciting to finally have the tools to see and map out the temperatures of a different planet in this much detail,\u201d Dr. Mansfield said.<\/p>\n

\u201cIt\u2019s set us up to possibly use the technique on other types of exoplanets. For example, if a planet doesn\u2019t have an atmosphere, we can still use the technique to map the temperature of the surface itself to possibly understand its composition.\u201d<\/p>\n

\u201cAlthough WASP-18b was more predictable, I believe we will have the chance to see things that we could never have expected before.\u201d<\/p>\n

The map of WASP-18b was published in a paper<\/a> in the journal Nature Astronomy.<\/p>\n

_____<\/p>\n

R.C. Challener et al. Horizontal and vertical exoplanet thermal structure from a JWST spectroscopic eclipse map. Nat Astron, published online October 28, 2025; doi: 10.1038\/s41550-025-02666-9<\/p>\n","protected":false},"excerpt":{"rendered":"The new map of WASP-18b, a hot-Jupiter exoplanet located approximately 325 light-years from Earth, reveals an atmosphere with…\n","protected":false},"author":2,"featured_media":106306,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[28195,3320,5676,76684,1022,5964,30684,76685,23226,3323,111,139,76686,69,147,13939,76687,76688,3329],"class_list":{"0":"post-106305","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-atmosphere","9":"tag-csa","10":"tag-eclipse","11":"tag-eclipse-mapping","12":"tag-esa","13":"tag-exoplanet","14":"tag-gas-giant","15":"tag-hot-jupiter","16":"tag-map","17":"tag-nasa","18":"tag-new-zealand","19":"tag-newzealand","20":"tag-niriss","21":"tag-nz","22":"tag-science","23":"tag-temperature","24":"tag-wasp-18","25":"tag-wasp-18b","26":"tag-webb"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/106305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=106305"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/106305\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/106306"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=106305"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=106305"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=106305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}