{"id":6855,"date":"2024-07-02T15:18:03","date_gmt":"2024-07-02T15:18:03","guid":{"rendered":"https:\/\/starbottle.space\/?p=6855"},"modified":"2024-07-02T15:18:04","modified_gmt":"2024-07-02T15:18:04","slug":"ltt9779b-il-luminosissimo-esopianeta-specchio","status":"publish","type":"post","link":"https:\/\/starbottle.space\/fr\/ltt9779b-lexoplanete-miroir-tres-lumineuse\/","title":{"rendered":"LTT9779b, l'exoplan\u00e8te \u201cmiroir\u201d tr\u00e8s brillante\u201d"},"content":{"rendered":"<p>Dans notre syst\u00e8me solaire, la plan\u00e8te la plus brillante est V\u00e9nus : sa proximit\u00e9 avec le Soleil et son atmosph\u00e8re lui conf\u00e8rent une r\u00e9flectivit\u00e9 tr\u00e8s \u00e9lev\u00e9e, \u00e9gale \u00e0 environ 75%.<\/p>\n\n\n\n<p>Il existe cependant une plan\u00e8te, d\u00e9couverte en 2020, qui d\u00e9passe cette valeur : elle s'appelle LTT 9779 b et est connue comme la plan\u00e8te \u201c miroir \u201d en raison de son incroyable luminosit\u00e9.<\/p>\n\n\n\n<p>Il se trouve \u00e0 environ 260 ann\u00e9es-lumi\u00e8re de nous et est une \u201c Neptune chaude \u201d, avec une masse similaire \u00e0 celle de Neptune mais beaucoup plus proche de son \u00e9toile, effectuant en effet une orbite en moins d'une journ\u00e9e. Sa proximit\u00e9 avec l'\u00e9toile le rend extr\u00eamement chaud, avec des temp\u00e9ratures sup\u00e9rieures \u00e0 1 700 degr\u00e9s Celsius.<\/p>\n\n\n\n<p>Mais le plus fascinant dans cet univers exotique, c'est son atmosph\u00e8re riche en m\u00e9taux et en silicates, qui r\u00e9fl\u00e9chit environ 80% de la lumi\u00e8re qu'elle re\u00e7oit. Cela en fait l'une des exoplan\u00e8tes les plus r\u00e9fl\u00e9chissantes jamais d\u00e9couvertes.<\/p>\n\n\n\n<p>Et pour nous, un laboratoire naturel pour \u00e9tudier les atmosph\u00e8res exoplan\u00e9taires : comment une plan\u00e8te parvient-elle \u00e0 conserver une atmosph\u00e8re dans des conditions aussi extr\u00eames ?<\/p>","protected":false},"excerpt":{"rendered":"<p>Nel nostro Sistema Solare, il pianeta pi\u00f9 luminoso di tutti \u00e8 Venere: la sua vicinanza al Sole e la sua atmosfera fanno s\u00ec che abbiamo una riflettivit\u00e0 molto elevata, pari a circa il 75%. C\u2019\u00e8 per\u00f2 un pianeta, che abbiamo scoperto nel 2020, che supera questo valore: si chiama LTT 9779 b ed \u00e8 noto [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6842,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"wds_primary_category":44,"footnotes":""},"categories":[44],"tags":[],"class_list":["post-6855","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vita-nello-spazio"],"acf":[],"_links":{"self":[{"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/posts\/6855","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/comments?post=6855"}],"version-history":[{"count":1,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/posts\/6855\/revisions"}],"predecessor-version":[{"id":6856,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/posts\/6855\/revisions\/6856"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/media\/6842"}],"wp:attachment":[{"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/media?parent=6855"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/categories?post=6855"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starbottle.space\/fr\/wp-json\/wp\/v2\/tags?post=6855"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}