{"id":55093,"date":"2026-03-22T00:12:20","date_gmt":"2026-03-22T00:12:20","guid":{"rendered":"https:\/\/www.africa-press.net\/benin\/politique\/decouverte-dune-exoplanete-unique-par-le-telescope-webb"},"modified":"2026-04-18T03:45:39","modified_gmt":"2026-04-18T03:45:39","slug":"decouverte-dune-exoplanete-unique-par-le-telescope-webb","status":"publish","type":"post","link":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb","title":{"rendered":"D\u00e9couverte d’une Exoplan\u00e8te Unique par le T\u00e9lescope Webb"},"content":{"rendered":"

Africa-Press – Benin. <\/strong> <\/span>A\u0300 environ 35 anne\u0301es-lumie\u0300re de la Terre, une petite plane\u0300te intrigue les astronomes. Les observations du te\u0301lescope spatial James Webb indiquent que L 98-59 d ne correspond a\u0300 aucune cate\u0301gorie classique de plane\u0300te connue. Ni ve\u0301ritable plane\u0300te rocheuse, ni monde domine\u0301 par l’eau, elle semble posse\u0301der un inte\u0301rieur entie\u0300rement fondu capable de stocker d’importantes quantite\u0301s de soufre.<\/p>\n

Un monde volcanique aux proprie\u0301te\u0301s inattendues<\/b><\/p>\n

L 98-59 d gravite autour d’une naine rouge de la constellation du Poisson austral. Sa taille atteint environ 1,6 fois celle de la Terre, mais sa densite\u0301 apparai\u0302t e\u0301tonnamment faible pour un monde de ce type. Les observations re\u0301alise\u0301es avec le te\u0301lescope spatial James Webb ont re\u0301ve\u0301le\u0301 dans son atmosphe\u0300re la pre\u0301sence de gaz soufre\u0301s, notamment du sulfure d’hydroge\u0300ne (H2S) et du dioxyde de soufre. Le sulfure d’hydroge\u0300ne est une mole\u0301cule bien connue sur Terre pour son odeur caracte\u0301ristique d’\u0153uf pourri, mais sur cette plane\u0300te il semble jouer un ro\u0302le beaucoup plus fondamental.<\/p>\n

Pour comprendre cette signature chimique inhabituelle, des chercheurs de l’universite\u0301 d’Oxford, de l’universite\u0301 de Groningen, de l’universite\u0301 de Leeds et de l’ETH Zurich ont utilise\u0301 des simulations nume\u0301riques pour reconstruire l’histoire de la plane\u0300te depuis sa formation. Les re\u0301sultats sont publie\u0301s dans la revue Nature Astronomy.<\/p>\n

Les mode\u0300les indiquent que le manteau de L 98-59 d serait constitue\u0301 de silicates fondus, autrement dit d’un oce\u0301an global de magma pouvant s’e\u0301tendre sur plusieurs milliers de kilome\u0300tres de profondeur. Ce re\u0301servoir interne agirait comme une gigantesque \u00ab\u00a0e\u0301ponge chimique\u00a0\u00bb, capable d’absorber et de rela\u0302cher du soufre sur des milliards d’anne\u0301es. \u00ab\u00a0Cette de\u0301couverte sugge\u0300re que les cate\u0301gories que les astronomes utilisent pour de\u0301crire les petites plane\u0300tes sont probablement trop simples\u00a0\u00bb, explique dans un communique\u0301 Harrison Nicholls, premier auteur de l’e\u0301tude. \u00ab\u00a0Ce monde en fusion est peu susceptible d’abriter la vie, mais il montre a\u0300 quel point la diversite\u0301 des plane\u0300tes peut e\u0302tre grande\u00a0\u00bb.<\/p>\n

Quand un oce\u0301an de magma fac\u0327onne une atmosphe\u0300re<\/b><\/p>\n

Les plane\u0300tes rocheuses naissent ge\u0301ne\u0301ralement sous forme d’astres partiellement fondus apre\u0300s leur formation. La Terre elle-me\u0302me aurait posse\u0301de\u0301 un oce\u0301an global de magma durant ses premiers millions d’anne\u0301es. Sur L 98-59 d, ce stade primordial pourrait simplement avoir dure\u0301 beaucoup plus longtemps. Selon les simulations, l’inte\u0301rieur fondu de la plane\u0300te agit comme un re\u0301servoir capable de pie\u0301ger de grandes quantite\u0301s de compose\u0301s volatils contenant du soufre. Ces gaz peuvent ensuite e\u0302tre libe\u0301re\u0301s progressivement dans l’atmosphe\u0300re, ou\u0300 ils subissent des re\u0301actions chimiques sous l’effet du rayonnement ultraviolet de l’e\u0301toile L 98-59.<\/p>\n

Ce me\u0301canisme expliquerait a\u0300 la fois la composition actuelle de l’atmosphe\u0300re et la faible densite\u0301 globale de la plane\u0300te. Les mode\u0300les sugge\u0300rent aussi que L 98-59 d pourrait e\u0302tre le vestige d’une plane\u0300te initialement plus grande, proche d’un sous-Neptune riche en gaz, qui aurait progressivement perdu une partie de son atmosphe\u0300re au cours des milliards d’anne\u0301es. Cette exoplane\u0300te pourrait ainsi repre\u0301senter le premier exemple identifie\u0301 d’une population entie\u0300re de plane\u0300tes riches en soufre et posse\u0301dant des oce\u0301ans de magma durables. Avec les futures observations du te\u0301lescope James Webb et les missions spatiales Ariel et PLATO, les astronomes espe\u0300rent de\u0301sormais de\u0301terminer si ces mondes au parfum de soufre sont rares ou, au contraire, relativement communs dans la galaxie.<\/p>\n

Retrouvez plus d\u2019actualit\u00e9s et d\u2019analyses sur Benin<\/span> sur le site Africa Press<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Africa-Press – Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de la Terre, une petite plane\u0300te intrigue les astronomes. Les observations du te\u0301lescope spatial James Webb indiquent que L 98-59 d ne correspond a\u0300 aucune cate\u0301gorie classique de plane\u0300te connue. Ni ve\u0301ritable plane\u0300te rocheuse, ni monde domine\u0301 par l’eau, elle semble posse\u0301der un inte\u0301rieur entie\u0300rement fondu capable de […]<\/p>\n","protected":false},"author":82,"featured_media":55092,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,10],"tags":[45],"class_list":["post-55093","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-divers","category-toutes-les-actualites","tag-benin"],"yoast_head":"\nD\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb - B\u00e9nin<\/title>\n<meta name=\"description\" content=\"-article-header-tag"> Africa-Press - Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de ...\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb\" \/>\n<meta property=\"og:description\" content=\"-article-header-tag"> Africa-Press - Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de ...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\" \/>\n<meta property=\"og:site_name\" content=\"B\u00e9nin\" \/>\n<meta property=\"article:published_time\" content=\"2026-03-22T00:12:20+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-04-18T03:45:39+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"900\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"cfeditorfr\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u00c9crit par\" \/>\n\t<meta name=\"twitter:data1\" content=\"cfeditorfr\" \/>\n\t<meta name=\"twitter:label2\" content=\"Dur\u00e9e de lecture estim\u00e9e\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\"},\"author\":{\"name\":\"cfeditorfr\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1\"},\"headline\":\"D\u00e9couverte d’une Exoplan\u00e8te Unique par le T\u00e9lescope Webb\",\"datePublished\":\"2026-03-22T00:12:20+00:00\",\"dateModified\":\"2026-04-18T03:45:39+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\"},\"wordCount\":670,\"commentCount\":0,\"image\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage\"},\"thumbnailUrl\":\"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg\",\"keywords\":[\"B\u00e9nin\"],\"articleSection\":[\"Divers\",\"Toutes les actualit\u00e9s\"],\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\",\"url\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\",\"name\":\"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb - B\u00e9nin\",\"isPartOf\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage\"},\"thumbnailUrl\":\"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg\",\"datePublished\":\"2026-03-22T00:12:20+00:00\",\"dateModified\":\"2026-04-18T03:45:39+00:00\",\"author\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1\"},\"description\":\"-article-header-tag\\\"> Africa-Press - Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de ...\",\"breadcrumb\":{\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#breadcrumb\"},\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage\",\"url\":\"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg\",\"contentUrl\":\"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg\",\"width\":1200,\"height\":900,\"caption\":\"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Accueil\",\"item\":\"https:\/\/www.africa-press.net\/benin\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"D\u00e9couverte d’une Exoplan\u00e8te Unique par le T\u00e9lescope Webb\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/#website\",\"url\":\"https:\/\/www.africa-press.net\/benin\/\",\"name\":\"B\u00e9nin\",\"description\":\"Just another Africa News Agency Sites site\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.africa-press.net\/benin\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"fr-FR\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.africa-press.net\/benin\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1\",\"name\":\"cfeditorfr\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb - B\u00e9nin","description":"-article-header-tag\"> Africa-Press - Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de ...","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb","og_locale":"fr_FR","og_type":"article","og_title":"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb","og_description":"-article-header-tag\"> Africa-Press - Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de ...","og_url":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb","og_site_name":"B\u00e9nin","article_published_time":"2026-03-22T00:12:20+00:00","article_modified_time":"2026-04-18T03:45:39+00:00","og_image":[{"width":1200,"height":900,"url":"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg","type":"image\/jpeg"}],"author":"cfeditorfr","twitter_card":"summary_large_image","twitter_misc":{"\u00c9crit par":"cfeditorfr","Dur\u00e9e de lecture estim\u00e9e":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#article","isPartOf":{"@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb"},"author":{"name":"cfeditorfr","@id":"https:\/\/www.africa-press.net\/benin\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1"},"headline":"D\u00e9couverte d’une Exoplan\u00e8te Unique par le T\u00e9lescope Webb","datePublished":"2026-03-22T00:12:20+00:00","dateModified":"2026-04-18T03:45:39+00:00","mainEntityOfPage":{"@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb"},"wordCount":670,"commentCount":0,"image":{"@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage"},"thumbnailUrl":"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg","keywords":["B\u00e9nin"],"articleSection":["Divers","Toutes les actualit\u00e9s"],"inLanguage":"fr-FR","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb","url":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb","name":"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb - B\u00e9nin","isPartOf":{"@id":"https:\/\/www.africa-press.net\/benin\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage"},"image":{"@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage"},"thumbnailUrl":"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg","datePublished":"2026-03-22T00:12:20+00:00","dateModified":"2026-04-18T03:45:39+00:00","author":{"@id":"https:\/\/www.africa-press.net\/benin\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1"},"description":"-article-header-tag\"> Africa-Press - Benin. A\u0300 environ 35 anne\u0301es-lumie\u0300re de ...","breadcrumb":{"@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#breadcrumb"},"inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#primaryimage","url":"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg","contentUrl":"https:\/\/static.africa-press.net\/benin\/sites\/46\/2026\/04\/sm_1776480376.951436.jpg","width":1200,"height":900,"caption":"D\u00e9couverte d'une Exoplan\u00e8te Unique par le T\u00e9lescope Webb"},{"@type":"BreadcrumbList","@id":"https:\/\/www.africa-press.net\/benin\/toutes-les-actualites\/decouverte-dune-exoplanete-unique-par-le-telescope-webb#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Accueil","item":"https:\/\/www.africa-press.net\/benin\/"},{"@type":"ListItem","position":2,"name":"D\u00e9couverte d’une Exoplan\u00e8te Unique par le T\u00e9lescope Webb"}]},{"@type":"WebSite","@id":"https:\/\/www.africa-press.net\/benin\/#website","url":"https:\/\/www.africa-press.net\/benin\/","name":"B\u00e9nin","description":"Just another Africa News Agency Sites site","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.africa-press.net\/benin\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"fr-FR"},{"@type":"Person","@id":"https:\/\/www.africa-press.net\/benin\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1","name":"cfeditorfr"}]}},"_links":{"self":[{"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/posts\/55093","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/users\/82"}],"replies":[{"embeddable":true,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/comments?post=55093"}],"version-history":[{"count":1,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/posts\/55093\/revisions"}],"predecessor-version":[{"id":55198,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/posts\/55093\/revisions\/55198"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/media\/55092"}],"wp:attachment":[{"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/media?parent=55093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/categories?post=55093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.africa-press.net\/benin\/wp-json\/wp\/v2\/tags?post=55093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}