{"id":7777,"date":"2017-06-12T17:13:27","date_gmt":"2017-06-12T17:13:27","guid":{"rendered":"https:\/\/blogs.futura-sciences.com\/feldmann\/?p=7777"},"modified":"2017-06-22T16:36:25","modified_gmt":"2017-06-22T16:36:25","slug":"61-cygni-premiere-etoile-dont-on-a-mesure-distance","status":"publish","type":"post","link":"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/","title":{"rendered":"61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance"},"content":{"rendered":"

En 1838 l’\u00e9toile 61 Cygni<\/em> fut la premi\u00e8re dont l’astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l’Univers. \u00a0<\/strong><\/p>\n

La constellation du Cygne, appel\u00e9e aussi la Croix du Nord (par comparaison \u00e0 la Croix du Sud<\/a>) ressemble \u00e0 un grand oiseau qui traverse la Voie lact\u00e9e<\/a> les nuits d’\u00e9t\u00e9 et se dirige vers le sud : la t\u00eate du volatile correspond \u00e0 l’\u00e9toile B\u00eata Cygni<\/em> (Albir\u00e9o) \u00e0 la limite de la constellation du Petit Renard alors que la queue est marqu\u00e9e par Alpha Cygni<\/em> (Deneb), l’une des composantes du Triangle d’\u00e9t\u00e9<\/a>.<\/p>\n

\"\"<\/a><\/p>\n

C’est \u00e0 proximit\u00e9 de Deneb que se situe 61 Cygni, une modeste \u00e9toile de magnitude<\/a> 5,2 qui a perdu son anonymat au XIXe si\u00e8cle lorsqu’on est parvenu \u00e0 mesurer sa distance.<\/p>\n

Au d\u00e9but des ann\u00e9es 1800 les astronomes<\/a> observaient principalement les \u00e9toiles \u00e0 l’aide de grandes lunettes comme celle de l’Observatoire de Nice<\/a> dans le but de mesurer leur position dans le ciel (c’est l’astrom\u00e9trie) et de d\u00e9couvrir d’\u00e9ventuels syst\u00e8mes d’\u00e9toiles doubles ou multiples. Personne alors ne pouvait estimer la distance qui nous s\u00e9parait de ces astres, m\u00eame si on les imaginait loin du Syst\u00e8me solaire. Seule la mesure de la parallaxe (la diff\u00e9rence de position d’une \u00e9toile proche par rapport au fond du ciel lorsque la Terre occupe deux positions oppos\u00e9es de son orbite autour du Soleil<\/a>) pouvait r\u00e9pondre \u00e0 cette question, mais quelles \u00e9toiles choisir pour tenter cette mesure ?<\/p>\n

\"\"<\/a>
Localisation de l’\u00e9toile 61 Cygni, la premi\u00e8re dont la distance fut mesur\u00e9e en 1838.<\/figcaption><\/figure>\n

C’est\u00a0l’astronome italien Giuseppe Piazzi, c\u00e9l\u00e8bre pour sa d\u00e9couverte de l’ast\u00e9ro\u00efde C\u00e9r\u00e8s<\/a> en 1801, qui remarqua le premier le d\u00e9placement relativement rapide de 61 Cygni (5 secondes d’arc par an, soit en gros un diam\u00e8tre lunaire en 350 ans !) : il mesura ce d\u00e9placement pendant plusieurs mois sans pour autant calculer la distance de l’\u00e9toile. C’est le math\u00e9maticien et astronome allemand Friedrich Bessel qui le fit en 1838 et trouva alors une distance de 10,3 ann\u00e9es-lumi\u00e8re. On admet aujourd’hui une distance de 11,4 AL, soit cent mille milliards de km : la mesure de la distance de 61 Cygni modifia brutalement le volume de l’Univers que les astronomes imaginaient alors.<\/p>\n

L’image qui illustre cet article a \u00e9t\u00e9 r\u00e9alis\u00e9e en additionnant 2 poses de 30 secondes \u00e0 3200 iso avec un objectif Samyang de 8 millim\u00e8tres de focale ouvert \u00e0 3.5 mont\u00e9 sur un bo\u00eetier Nikon D3200 (sur pied photo sans compensation de la rotation terrestre) au cours d’un s\u00e9jour en Indre-et-Loire<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

En 1838 l’\u00e9toile 61 Cygni fut la premi\u00e8re dont l’astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l’Univers. \u00a0 La constellation du Cygne, appel\u00e9e aussi la Croix du Nord (par comparaison \u00e0 la Croix du Sud) ressemble \u00e0 un grand oiseau qui traverse la Voie lact\u00e9e les nuits d’\u00e9t\u00e9 et … Continuer la lecture de 61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":8,"featured_media":7778,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[84],"tags":[2191,2194,102,101,2192,2193,854,935],"class_list":["post-7777","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ciel-etoile","tag-61-cygni","tag-albireo","tag-constellation-du-cygne","tag-deneb","tag-etoile-de-bessel","tag-friedrich-bessel","tag-giuseppe-piazzi","tag-triangle-dete"],"yoast_head":"\n61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance<\/title>\n<meta name=\"description\" content=\"En 1838 l'\u00e9toile 61 Cygni fut la premi\u00e8re dont l'astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l'Univers.\" \/>\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\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance\" \/>\n<meta property=\"og:description\" content=\"En 1838 l'\u00e9toile 61 Cygni fut la premi\u00e8re dont l'astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l'Univers.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/\" \/>\n<meta property=\"og:site_name\" content=\"CIELMANIA : le blog de Jean-Baptiste FELDMANN, photographe du ciel\" \/>\n<meta property=\"article:published_time\" content=\"2017-06-12T17:13:27+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2017-06-22T16:36:25+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1354\" \/>\n\t<meta property=\"og:image:height\" content=\"900\" \/>\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\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/\",\"url\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/\",\"name\":\"61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance\",\"isPartOf\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg\",\"datePublished\":\"2017-06-12T17:13:27+00:00\",\"dateModified\":\"2017-06-22T16:36:25+00:00\",\"author\":{\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/62b391b709c307783237b759b62731ea\"},\"description\":\"En 1838 l'\u00e9toile 61 Cygni fut la premi\u00e8re dont l'astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l'Univers.\",\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/#primaryimage\",\"url\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg\",\"contentUrl\":\"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg\",\"width\":1354,\"height\":900},{\"@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":"61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance","description":"En 1838 l'\u00e9toile 61 Cygni fut la premi\u00e8re dont l'astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l'Univers.","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\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/","og_locale":"fr_FR","og_type":"article","og_title":"61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance","og_description":"En 1838 l'\u00e9toile 61 Cygni fut la premi\u00e8re dont l'astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l'Univers.","og_url":"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/","og_site_name":"CIELMANIA : le blog de Jean-Baptiste FELDMANN, photographe du ciel","article_published_time":"2017-06-12T17:13:27+00:00","article_modified_time":"2017-06-22T16:36:25+00:00","og_image":[{"width":1354,"height":900,"url":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.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\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/","url":"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/","name":"61 Cygni, premi\u00e8re \u00e9toile dont on a mesur\u00e9 la distance","isPartOf":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#website"},"primaryImageOfPage":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/#primaryimage"},"image":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/#primaryimage"},"thumbnailUrl":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg","datePublished":"2017-06-12T17:13:27+00:00","dateModified":"2017-06-22T16:36:25+00:00","author":{"@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/#\/schema\/person\/62b391b709c307783237b759b62731ea"},"description":"En 1838 l'\u00e9toile 61 Cygni fut la premi\u00e8re dont l'astronome Friedrich Bessel mesura la distance, un r\u00e9sultat qui bouleversa notre vision de l'Univers.","inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/blogs.futura-sciences.com\/feldmann\/2017\/06\/12\/61-cygni-premiere-etoile-dont-on-a-mesure-distance\/#primaryimage","url":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg","contentUrl":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-content\/uploads\/sites\/9\/2017\/04\/cygni.jpg","width":1354,"height":900},{"@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\/7777","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=7777"}],"version-history":[{"count":8,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/posts\/7777\/revisions"}],"predecessor-version":[{"id":7989,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/posts\/7777\/revisions\/7989"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/media\/7778"}],"wp:attachment":[{"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/media?parent=7777"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/categories?post=7777"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.futura-sciences.com\/feldmann\/wp-json\/wp\/v2\/tags?post=7777"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}