{"id":11263,"date":"2019-10-25T08:18:25","date_gmt":"2019-10-25T08:18:25","guid":{"rendered":"https:\/\/blogs.futura-sciences.com\/feldmann\/?p=11263"},"modified":"2019-11-06T06:35:24","modified_gmt":"2019-11-06T06:35:24","slug":"collisions-de-cometes-autour-de-l-etoile-fomalhaut","status":"publish","type":"post","link":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/","title":{"rendered":"Incessantes collisions de com\u00e8tes autour de l’\u00e9toile Fomalhaut"},"content":{"rendered":"

Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.<\/strong><\/p>\n

Carte d’identit\u00e9 :<\/h5>\n

Si vous sortez admirer le ciel aux alentours de minuit, vous rep\u00e9rerez ais\u00e9ment le carr\u00e9 de P\u00e9gase<\/a> plein sud. En abaissant votre regard en direction de l’horizon, vous remarquerez une \u00e9toile de magnitude<\/a> 1 dans une r\u00e9gion pauvre en astres brillants. Il s’agit de Fomalhaut dans la constellation du Poisson austral. C’est une \u00e9toile jeune (400 millions d’ann\u00e9es environ) et blanche. Elle se trouve \u00e0 environ 25 ann\u00e9es-lumi\u00e8re de nous. Elle est deux fois plus grande, deux fois plus massive et seize fois plus lumineuse que le Soleil<\/a>.<\/p>\n

\"\"<\/a>
Carte de rep\u00e9rage de Fomalhaut pendant le mois d’octobre vers minuit. \u00a9 Stelvision<\/figcaption><\/figure>\n

L\u00e9gende ou histoire v\u00e9ridique ? On raconte qu’il y a 3.000 ans, en Perse (l’actuel Iran), Fomalhaut \u00e9tait l’une des quatre \u00e9toiles royales. Elle tr\u00f4nait dans l’une des quatre r\u00e9gions c\u00e9lestes, les autres \u00e9tant gouvern\u00e9es par Ald\u00e9baran<\/a>, R\u00e9gulus<\/a> et Antar\u00e8s<\/a>.<\/p>\n

l’Oeil de Sauron :<\/h5>\n

Pour les astronomes d’aujourd’hui, Fomalhaut a bien d’autres atouts. On a d\u00e9couvert par exemple qu’elle est entour\u00e9e d’un anneau qui se compose de glace et de poussi\u00e8res. On imagine qu’il s’y produit de multiples collisions entre des com\u00e8tes<\/a> et de futures plan\u00e8tes, des plan\u00e9t\u00e9simaux. En combinant les donn\u00e9es du r\u00e9seau ALMA<\/a> et du t\u00e9lescope Hubble<\/a> on obtient une fascinante image de cet anneau qui fait penser \u00e0 un \u0153il gigantesque (ci-dessous). On le surnomme d’ailleurs l’Oeil de Sauron, l’un des personnages du Seigneur des Anneaux.<\/p>\n

\"\"<\/a>
Un anneau de glace et de poussi\u00e8re entoure l’\u00e9toile Fomalhaut. \u00a9 ALMA\/NASA\/Hubble<\/figcaption><\/figure>\n
Compagne stellaire :<\/h5>\n

Mais ce n’est pas tout. Dans son d\u00e9placement au sein de notre Galaxie<\/a>, Fomalhaut est accompagn\u00e9e par une \u00e9toile naine faible (magnitude 6,5) connue sous le nom de TW Piscis Austrini<\/em> (ou Fomalhaut B). Est-ce un syst\u00e8me binaire ? Probablement pas, la distance entre les deux astres (une ann\u00e9e-lumi\u00e8re) \u00e9tant beaucoup trop grande. On imagine que ces deux \u00e9toiles qui voguent de concert trahissent leur naissance commune au sein d’un amas stellaire dilu\u00e9 dans l’espace depuis longtemps. Le satellite TESS<\/a> (Transiting Exoplanet Survey Satellite<\/em>) semble avoir d\u00e9tect\u00e9 une possible exoplan\u00e8te de la taille de la Terre en orbite autour de TW Piscis Austrini<\/em>. D’autres observations seront n\u00e9cessaires pour confirmer l’existence de cette exoterre.<\/p>\n","protected":false},"excerpt":{"rendered":"

Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res. Carte d’identit\u00e9 : Si vous sortez admirer le ciel aux alentours de minuit, vous rep\u00e9rerez ais\u00e9ment le carr\u00e9 de P\u00e9gase plein sud. En abaissant votre regard en direction de l’horizon, vous remarquerez une \u00e9toile de magnitude … Continuer la lecture de Incessantes collisions de com\u00e8tes autour de l’\u00e9toile Fomalhaut<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":8,"featured_media":11265,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[84],"tags":[1048,377,375,544,2727,2728],"class_list":["post-11263","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ciel-etoile","tag-alma","tag-constellation-du-poisson-austral","tag-fomalhaut","tag-telescope-spatial-hubble","tag-tess","tag-tw-piscis-austrini"],"yoast_head":"\nIncessantes collisions de com\u00e8tes autour de l'\u00e9toile Fomalhaut<\/title>\n<meta name=\"description\" content=\"Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Incessantes collisions de com\u00e8tes autour de l'\u00e9toile Fomalhaut\" \/>\n<meta property=\"og:description\" content=\"Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/\" \/>\n<meta property=\"og:site_name\" content=\"CIELMANIA : le blog de Jean-Baptiste FELDMANN, photographe du ciel\" \/>\n<meta property=\"article:published_time\" content=\"2019-10-25T08:18:25+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2019-11-06T06:35:24+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1080\" \/>\n\t<meta property=\"og:image:height\" content=\"699\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Jean-Baptiste FELDMANN\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u00c9crit par\" \/>\n\t<meta name=\"twitter:data1\" content=\"Jean-Baptiste FELDMANN\" \/>\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\":\"WebPage\",\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/\",\"url\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/\",\"name\":\"Incessantes collisions de com\u00e8tes autour de l'\u00e9toile Fomalhaut\",\"isPartOf\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg\",\"datePublished\":\"2019-10-25T08:18:25+00:00\",\"dateModified\":\"2019-11-06T06:35:24+00:00\",\"author\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/62b391b709c307783237b759b62731ea\"},\"description\":\"Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.\",\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/#primaryimage\",\"url\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg\",\"contentUrl\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg\",\"width\":1080,\"height\":699,\"caption\":\"Un anneau de glace et de poussi\u00e8re entoure l'\u00e9toile Fomalhaut. \u00a9 ALMA\/NASA\/Hubble\"},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#website\",\"url\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/\",\"name\":\"CIELMANIA : le blog de Jean-Baptiste FELDMANN, photographe du ciel\",\"description\":\""J'ai en moi un besoin terrible. Dirais-je le mot? La religion. Alors, je sors la nuit et je peins des \u00e9toiles." Vincent van Gogh\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"fr-FR\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/62b391b709c307783237b759b62731ea\",\"name\":\"Jean-Baptiste FELDMANN\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/41f96607fde7a81a14570eec74177c42?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/41f96607fde7a81a14570eec74177c42?s=96&d=mm&r=g\",\"caption\":\"Jean-Baptiste FELDMANN\"},\"url\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/author\/jbfe\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Incessantes collisions de com\u00e8tes autour de l'\u00e9toile Fomalhaut","description":"Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.","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:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/","og_locale":"fr_FR","og_type":"article","og_title":"Incessantes collisions de com\u00e8tes autour de l'\u00e9toile Fomalhaut","og_description":"Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.","og_url":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/","og_site_name":"CIELMANIA : le blog de Jean-Baptiste FELDMANN, photographe du ciel","article_published_time":"2019-10-25T08:18:25+00:00","article_modified_time":"2019-11-06T06:35:24+00:00","og_image":[{"width":1080,"height":699,"url":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg","type":"image\/jpeg"}],"author":"Jean-Baptiste FELDMANN","twitter_card":"summary_large_image","twitter_misc":{"\u00c9crit par":"Jean-Baptiste FELDMANN","Dur\u00e9e de lecture estim\u00e9e":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/","url":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/","name":"Incessantes collisions de com\u00e8tes autour de l'\u00e9toile Fomalhaut","isPartOf":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#website"},"primaryImageOfPage":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/#primaryimage"},"image":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/#primaryimage"},"thumbnailUrl":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg","datePublished":"2019-10-25T08:18:25+00:00","dateModified":"2019-11-06T06:35:24+00:00","author":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/62b391b709c307783237b759b62731ea"},"description":"Dans la constellation du Poisson austral, cherchez Fomalhaut. Cette \u00e9toile est entour\u00e9e d\u2019un disque de glace et de poussi\u00e8res.","inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2019\/10\/25\/collisions-de-cometes-autour-de-l-etoile-fomalhaut\/#primaryimage","url":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg","contentUrl":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2019\/10\/fomalhaut.jpg","width":1080,"height":699,"caption":"Un anneau de glace et de poussi\u00e8re entoure l'\u00e9toile Fomalhaut. \u00a9 ALMA\/NASA\/Hubble"},{"@type":"WebSite","@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#website","url":"https:\/\/blogs.futura-sciences.com\/feldmann\/","name":"CIELMANIA : le blog de Jean-Baptiste FELDMANN, photographe du ciel","description":""J'ai en moi un besoin terrible. Dirais-je le mot? La religion. Alors, je sors la nuit et je peins des \u00e9toiles." Vincent van Gogh","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/blogs.futura-sciences.com\/feldmann\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"fr-FR"},{"@type":"Person","@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/62b391b709c307783237b759b62731ea","name":"Jean-Baptiste FELDMANN","image":{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/41f96607fde7a81a14570eec74177c42?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/41f96607fde7a81a14570eec74177c42?s=96&d=mm&r=g","caption":"Jean-Baptiste FELDMANN"},"url":"https:\/\/blogs.futura-sciences.com\/feldmann\/author\/jbfe\/"}]}},"_links":{"self":[{"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/posts\/11263","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/comments?post=11263"}],"version-history":[{"count":2,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/posts\/11263\/revisions"}],"predecessor-version":[{"id":11323,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/posts\/11263\/revisions\/11323"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/media\/11265"}],"wp:attachment":[{"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/media?parent=11263"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/categories?post=11263"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/tags?post=11263"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}