{"id":111075,"date":"2025-12-27T13:29:58","date_gmt":"2025-12-27T13:29:58","guid":{"rendered":"https:\/\/www.africa-press.net\/cotedivoire\/politique\/planete-geante-et-naine-brune-observees-malgre-leclat"},"modified":"2025-12-27T14:27:23","modified_gmt":"2025-12-27T14:27:23","slug":"planete-geante-et-naine-brune-observees-malgre-leclat","status":"publish","type":"post","link":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat","title":{"rendered":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l’\u00e9clat"},"content":{"rendered":"

Africa-Press – C\u00f4te d’Ivoire. <\/strong><\/span>Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagnons suffisamment massifs et e\u0301loigne\u0301s pour e\u0302tre directement image\u0301s. Le programme OASIS vient pourtant de franchir une e\u0301tape avec deux objets de\u0301tecte\u0301s gra\u0302ce au te\u0301lescope Subaru, a\u0300 Hawai\u0308, en s\u2019appuyant sur une strate\u0301gie simple: utiliser d\u2019abord les mouvements infimes des e\u0301toiles mesure\u0301s depuis l\u2019espace pour savoir pre\u0301cise\u0301ment ou\u0300 pointer les instruments au sol.<\/p>\n

Quand l\u2019astrome\u0301trie montre la voie<\/b><\/p>\n

Le programme OASIS exploite les donne\u0301es des missions Hipparcos et Gaia de l\u2019Agence spatiale europe\u0301enne, capables de repe\u0301rer les oscillations minuscules d\u2019une e\u0301toile sous l\u2019effet gravitationnel d\u2019un compagnon invisible. Une fois la signature de\u0301tecte\u0301e, le te\u0301lescope Subaru est mobilise\u0301 avec son syste\u0300me d\u2019optique adaptative extre\u0302me SCExAO, conc\u0327u pour atte\u0301nuer la lumie\u0300re stellaire et re\u0301ve\u0301ler des objets bien plus faibles.<\/p>\n

C\u2019est ainsi qu\u2019a e\u0301te\u0301 photographie\u0301e HIP 54515 b, une plane\u0300te ge\u0301ante d\u2019environ 18 masses de Jupiter, situe\u0301e a\u0300 271 anne\u0301es-lumie\u0300re dans la constellation du Lion. Elle orbite a\u0300 une distance comparable a\u0300 celle de Neptune autour du Soleil, mais vue depuis la Terre, sa se\u0301paration avec son e\u0301toile e\u0301quivaut a\u0300 distinguer une balle de baseball a\u0300 100 kilome\u0300tres.<\/p>\n

Une cible ide\u0301ale pour les futurs coronographes<\/b><\/p>\n

La seconde de\u0301tection concerne HIP 71618 B, une naine brune d\u2019environ 60 masses de Jupiter, a\u0300 169 anne\u0301es-lumie\u0300re dans le Bouvier. Ces objets, souvent qualifie\u0301s d\u2019e\u0301toiles avorte\u0301es, inte\u0301ressent ici pour leur valeur technologique. HIP 71618 B re\u0301unit en effet toutes les conditions pour servir de cible de test au futur coronographe du Nancy Grace Roman Space Telescope.<\/p>\n

Cet instrument doit de\u0301montrer la capacite\u0301 a\u0300 imager des mondes jusqu\u2019a\u0300 dix milliards de fois plus faibles que leur e\u0301toile, un pre\u0301alable indispensable a\u0300 la recherche de plane\u0300tes de type terrestre. Au-dela\u0300 de ces deux objets, OASIS illustre un changement de me\u0301thode. L\u2019astrome\u0301trie spatiale ne se contente plus de dresser des catalogues, elle devient un outil de guidage pour l\u2019imagerie directe. Une coope\u0301ration entre espace et sol qui pourrait bien s\u2019imposer comme la norme pour traquer les mondes les plus discrets autour des e\u0301toiles proches.<\/p>\n

Pour plus d’informations et d’analyses sur la C\u00f4te d’Ivoire<\/span>, suivez Africa-Press<\/span><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Africa-Press – C\u00f4te d’Ivoire. Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagnons suffisamment massifs et e\u0301loigne\u0301s pour e\u0302tre directement image\u0301s. Le programme OASIS vient pourtant de franchir une e\u0301tape avec deux objets de\u0301tecte\u0301s gra\u0302ce au te\u0301lescope Subaru, a\u0300 Hawai\u0308, en s\u2019appuyant sur une strate\u0301gie […]<\/p>\n","protected":false},"author":82,"featured_media":111074,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,10],"tags":[29],"class_list":["post-111075","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-divers","category-toutes-les-actualites","tag-cote-divoire"],"yoast_head":"\nPlan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat - C\u00f4te d'Ivoire<\/title>\n<meta name=\"description\" content=\"Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagn ...\" \/>\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\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat\" \/>\n<meta property=\"og:description\" content=\"Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagn ...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\" \/>\n<meta property=\"og:site_name\" content=\"C\u00f4te d'Ivoire\" \/>\n<meta property=\"article:published_time\" content=\"2025-12-27T13:29:58+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-12-27T14:27:23+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.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=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\"},\"author\":{\"name\":\"cfeditorfr\",\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1\"},\"headline\":\"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l’\u00e9clat\",\"datePublished\":\"2025-12-27T13:29:58+00:00\",\"dateModified\":\"2025-12-27T14:27:23+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\"},\"wordCount\":445,\"commentCount\":0,\"image\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage\"},\"thumbnailUrl\":\"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg\",\"keywords\":[\"C\u00d4TE D'IVOIRE\"],\"articleSection\":[\"Divers\",\"Toutes les actualit\u00e9s\"],\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\",\"url\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\",\"name\":\"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat - C\u00f4te d'Ivoire\",\"isPartOf\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage\"},\"thumbnailUrl\":\"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg\",\"datePublished\":\"2025-12-27T13:29:58+00:00\",\"dateModified\":\"2025-12-27T14:27:23+00:00\",\"author\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1\"},\"description\":\"Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagn ...\",\"breadcrumb\":{\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#breadcrumb\"},\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage\",\"url\":\"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg\",\"contentUrl\":\"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg\",\"width\":1200,\"height\":900,\"caption\":\"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Accueil\",\"item\":\"https:\/\/www.africa-press.net\/cotedivoire\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l’\u00e9clat\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.africa-press.net\/cotedivoire\/#website\",\"url\":\"https:\/\/www.africa-press.net\/cotedivoire\/\",\"name\":\"C\u00f4te d'Ivoire\",\"description\":\"Just another Africa News Agency Sites site\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.africa-press.net\/cotedivoire\/?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\/cotedivoire\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1\",\"name\":\"cfeditorfr\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat - C\u00f4te d'Ivoire","description":"Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagn ...","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\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat","og_locale":"fr_FR","og_type":"article","og_title":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat","og_description":"Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagn ...","og_url":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat","og_site_name":"C\u00f4te d'Ivoire","article_published_time":"2025-12-27T13:29:58+00:00","article_modified_time":"2025-12-27T14:27:23+00:00","og_image":[{"width":1200,"height":900,"url":"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg","type":"image\/jpeg"}],"author":"cfeditorfr","twitter_card":"summary_large_image","twitter_misc":{"\u00c9crit par":"cfeditorfr","Dur\u00e9e de lecture estim\u00e9e":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#article","isPartOf":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat"},"author":{"name":"cfeditorfr","@id":"https:\/\/www.africa-press.net\/cotedivoire\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1"},"headline":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l’\u00e9clat","datePublished":"2025-12-27T13:29:58+00:00","dateModified":"2025-12-27T14:27:23+00:00","mainEntityOfPage":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat"},"wordCount":445,"commentCount":0,"image":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage"},"thumbnailUrl":"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg","keywords":["C\u00d4TE D'IVOIRE"],"articleSection":["Divers","Toutes les actualit\u00e9s"],"inLanguage":"fr-FR","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat","url":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat","name":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat - C\u00f4te d'Ivoire","isPartOf":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage"},"image":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage"},"thumbnailUrl":"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg","datePublished":"2025-12-27T13:29:58+00:00","dateModified":"2025-12-27T14:27:23+00:00","author":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1"},"description":"Voir des plane\u0300tes autour d\u2019autres e\u0301toiles reste une prouesse. Moins de 1 % des e\u0301toiles connues posse\u0300dent des compagn ...","breadcrumb":{"@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#breadcrumb"},"inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#primaryimage","url":"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg","contentUrl":"https:\/\/static.africa-press.net\/cote\/sites\/43\/2025\/12\/sm_1766832930.408664.jpg","width":1200,"height":900,"caption":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l'\u00e9clat"},{"@type":"BreadcrumbList","@id":"https:\/\/www.africa-press.net\/cotedivoire\/toutes-les-actualites\/planete-geante-et-naine-brune-observees-malgre-leclat#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Accueil","item":"https:\/\/www.africa-press.net\/cotedivoire\/"},{"@type":"ListItem","position":2,"name":"Plan\u00e8te g\u00e9ante et naine brune observ\u00e9es malgr\u00e9 l’\u00e9clat"}]},{"@type":"WebSite","@id":"https:\/\/www.africa-press.net\/cotedivoire\/#website","url":"https:\/\/www.africa-press.net\/cotedivoire\/","name":"C\u00f4te d'Ivoire","description":"Just another Africa News Agency Sites site","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.africa-press.net\/cotedivoire\/?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\/cotedivoire\/#\/schema\/person\/2b1cf3cd81a31e3cd26889ca66d677f1","name":"cfeditorfr"}]}},"_links":{"self":[{"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/posts\/111075","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/users\/82"}],"replies":[{"embeddable":true,"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/comments?post=111075"}],"version-history":[{"count":0,"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/posts\/111075\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/media\/111074"}],"wp:attachment":[{"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/media?parent=111075"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/categories?post=111075"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.africa-press.net\/cotedivoire\/wp-json\/wp\/v2\/tags?post=111075"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}