{"id":8563,"date":"2015-10-18T00:00:23","date_gmt":"2015-10-17T22:00:23","guid":{"rendered":"http:\/\/www.laterredufutur.com\/accueil\/?p=8563"},"modified":"2015-10-18T08:09:17","modified_gmt":"2015-10-18T06:09:17","slug":"exoplanetes-2-000-decouvertes-en-vingt-ans","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/exoplanetes-2-000-decouvertes-en-vingt-ans\/","title":{"rendered":"Exoplan\u00e8tes : 2 000 d\u00e9couvertes en vingt ans"},"content":{"rendered":"<div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"1\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p style=\"text-align: justify;\">Le 6 octobre 1995, Michel Mayor et Didier Queloz, de l\u2019Observatoire de Gen\u00e8ve, annon\u00e7aient la d\u00e9couverte de la premi\u00e8re exoplan\u00e8te \u2013 une \u00ab super-Jupiter \u00bb \u2013 tournant autour d\u2019une \u00e9toile ressemblant \u00e0 notre Soleil. La chasse \u00e0 ces astres dont on soup\u00e7onnait l\u2019existence depuis l\u2019Antiquit\u00e9 \u00e9tait relanc\u00e9e, mais pendant plusieurs ann\u00e9es, la r\u00e9colte est rest\u00e9e maigre.<\/p>\n<p style=\"text-align: justify;\">Ces derni\u00e8res ann\u00e9es, elle a connu plus de succ\u00e8s, avec notamment l\u2019apport de deux satellites, l\u2019europ\u00e9en Corot et l\u2019am\u00e9ricain Kepler. Le total cumul\u00e9 des exoplan\u00e8tes confirm\u00e9es approche des 2 000, selon le d\u00e9compte minutieux de l\u2019Encyclop\u00e9die des plan\u00e8tes extrasolaires tenue par le Fran\u00e7ais Jean Schneider (qui sert de sources aux graphiques de cet article).<\/p>\n<p><a href=\"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/10\/decouvertes-exoplanetes-1995-2015.jpg\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"8564\" data-permalink=\"https:\/\/www.laterredufutur.com\/accueil\/exoplanetes-2-000-decouvertes-en-vingt-ans\/decouvertes-exoplanetes-1995-2015\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/10\/decouvertes-exoplanetes-1995-2015.jpg?fit=546%2C435&amp;ssl=1\" data-orig-size=\"546,435\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"decouvertes-exoplanetes-1995-2015\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/10\/decouvertes-exoplanetes-1995-2015.jpg?fit=546%2C435&amp;ssl=1\" class=\"alignnone size-full wp-image-8564\" src=\"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/10\/decouvertes-exoplanetes-1995-2015.jpg?resize=546%2C435\" alt=\"decouvertes-exoplanetes-1995-2015\" width=\"546\" height=\"435\" srcset=\"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/10\/decouvertes-exoplanetes-1995-2015.jpg?w=546&amp;ssl=1 546w, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/10\/decouvertes-exoplanetes-1995-2015.jpg?resize=300%2C239&amp;ssl=1 300w\" sizes=\"auto, (max-width: 546px) 100vw, 546px\" \/><\/a><\/p>\n<p style=\"text-align: justify;\">Le pic de d\u00e9tections de l\u2019ann\u00e9e 2014 est d\u00fb \u00e0 Kepler, premier observatoire spatial sp\u00e9cifiquement d\u00e9di\u00e9 \u00e0 la d\u00e9tection de plan\u00e8tes extrasolaires. La chute en 2015 tient au fait que cet instrument lanc\u00e9 en 2009 a perdu des gyroscopes, incident qui ne lui permet plus d\u2019effectuer une surveillance pr\u00e9cise de la portion de ciel qui lui \u00e9tait assign\u00e9e.<\/p><div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n\n<p>En\u00a01995, la premi\u00e8re exoplan\u00e8te avait \u00e9t\u00e9 d\u00e9couverte par la m\u00e9thode des vitesses radiales. Celle-ci consiste \u00e0 mesurer les variations de couleur de l\u2019\u00e9toile, induites par le mouvement de la plan\u00e8te autour d\u2019elle\u00a0: cette danse modifie l\u2019emplacement de l\u2019\u00e9toile autour de leur centre de gravit\u00e9 commun. Comme le son de la sir\u00e8ne d\u2019un camion de pompiers, plus aigu lorsqu\u2019il s\u2019approche, plus grave lorsqu\u2019il s\u2019\u00e9loigne, ces mouvements p\u00e9riodiques par rapport \u00e0 un observateur ext\u00e9rieur modifient la perception de la longueur d\u2019onde de la lumi\u00e8re \u00e9mise par l\u2019\u00e9toile \u2013 on parle d\u2019effet Doppler-Fizeau. Cette m\u00e9thode ne permet pour l\u2019heure de d\u00e9tecter que des plan\u00e8tes g\u00e9antes, de type Jupiter \u2013 comme celle d\u00e9couverte en\u00a01995 par Mayor et Queloz autour de l\u2019\u00e9toile 51\u00a0Peg.<\/p>\n<div id=\"mb_container\"><\/div>\n<p>Kepler utilise, lui, la technique, dite \u00ab\u00a0du transit\u00a0\u00bb, qui consiste \u00e0 d\u00e9tecter les variations de luminosit\u00e9 d\u2019une \u00e9toile lors du passage d\u2019une plan\u00e8te dans la ligne de vis\u00e9e de l\u2019observateur. Elle permet de d\u00e9duire la taille de la plan\u00e8te et sa distance \u00e0 l\u2019\u00e9toile \u2013 afin de savoir si elle se trouve dans la zone habitable, c\u2019est-\u00e0-dire \u00e0 une distance qui rend possible la pr\u00e9sence d\u2019eau liquide. Mais ne r\u00e9v\u00e8le pas la masse, si cruciale.<\/p>\n<p>source et extrait de <a href=\"http:\/\/www.lemonde.fr\" target=\"_blank\">http:\/\/www.lemonde.fr<\/a><\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"8563\">(300)<\/p>\n<!--CusAds0-->\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Le 6 octobre 1995, Michel Mayor et Didier Queloz, de l\u2019Observatoire de Gen\u00e8ve, annon\u00e7aient la d\u00e9couverte de la premi\u00e8re exoplan\u00e8te&#8230;<\/p>\n","protected":false},"author":1,"featured_media":1612,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"ngg_post_thumbnail":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[22],"tags":[538,359,4829,2068,875,1370],"class_list":["post-8563","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-espace","tag-decouverte","tag-exoplanete","tag-extrasolaires","tag-graphique","tag-kepler","tag-planetes","wpcat-22-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2013\/11\/pandora-exo.jpg?fit=450%2C253&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-2e7","jetpack-related-posts":[{"id":9701,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-decouverte-de-nouveaux-mondes-saccelere-deja-2-000-exoplanetes-recensees\/","url_meta":{"origin":8563,"position":0},"title":"La d\u00e9couverte de nouveaux mondes s&rsquo;acc\u00e9l\u00e8re : d\u00e9j\u00e0 2 000 exoplan\u00e8tes recens\u00e9es !","author":"Admin","date":"2 d\u00e9cembre 2015","format":false,"excerpt":"20 ans apr\u00e8s la d\u00e9couverte de la premi\u00e8re exoplan\u00e8te, l'Encyclop\u00e9die des plan\u00e8tes extrasolaires, tenue minutieusement par Jean Schneider, astronome de l'Observatoire de Paris, en d\u00e9nombre aujourd'hui plus de 2 000, alors que les r\u00e9centes \u00e9tudes estiment leur nombre \u00e0 plusieurs milliards ! La premi\u00e8re exoplan\u00e8te, appel\u00e9e 51 Peg b, fut\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/12\/exoplanetes-Terre.jpg?fit=900%2C617&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/12\/exoplanetes-Terre.jpg?fit=900%2C617&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/12\/exoplanetes-Terre.jpg?fit=900%2C617&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/12\/exoplanetes-Terre.jpg?fit=900%2C617&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":1352,"url":"https:\/\/www.laterredufutur.com\/accueil\/deux-super-terres-dans-une-zone-habitable\/","url_meta":{"origin":8563,"position":1},"title":"Deux super Terres dans une zone habitable","author":"Admin","date":"25 avril 2013","format":false,"excerpt":"Le satellite Kepler, de la Nasa, vient de d\u00e9busquer un syst\u00e8me plan\u00e9taire remarquable constitu\u00e9 de cinq plan\u00e8tes, dont deux sont dans la zone habitable. Une p\u00e9pite pour l'exobiologie Retenez ce nom : Kepler 62. C'est ainsi qu'est baptis\u00e9 le syst\u00e8me extrasolaire le plus prometteur pour les exobiologistes. Il est situ\u00e9\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"kepler","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2011\/12\/kepler-0.jpg?fit=494%2C351&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":12608,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-telescope-kepler-decouvre-une-exoplanete-de-la-taille-de-jupiter-et-potentiellement-habitable\/","url_meta":{"origin":8563,"position":2},"title":"Le t\u00e9lescope Kepler d\u00e9couvre une exoplan\u00e8te de la taille de Jupiter et potentiellement habitable","author":"Admin","date":"24 juin 2016","format":false,"excerpt":"Kepler-1647b \u00e9volue en orbite autour de deux \u00e9toiles et \u00e0 une distance de ses astres qui la rend potentiellement habitable... Le t\u00e9lescope orbital am\u00e9ricain Kepler vient de d\u00e9couvrir une nouvelle plan\u00e8te. Baptis\u00e9e Kepler-1647b, cette exoplan\u00e8te pr\u00e9sente d\u2019abord la particularit\u00e9 d\u2019\u00eatre aussi grande que Jupiter, initialement la plus grosse plan\u00e8te de\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/06\/Kepler-1647b.jpg?fit=800%2C480&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/06\/Kepler-1647b.jpg?fit=800%2C480&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/06\/Kepler-1647b.jpg?fit=800%2C480&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/06\/Kepler-1647b.jpg?fit=800%2C480&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":10644,"url":"https:\/\/www.laterredufutur.com\/accueil\/planetes-habitables-les-decouvertes-de-kepler\/","url_meta":{"origin":8563,"position":3},"title":"Plan\u00e8tes habitables, les d\u00e9couvertes de Kepler","author":"Admin","date":"28 janvier 2016","format":false,"excerpt":"Sommes-nous seuls dans l'Univers ? \u00c0 partir des donn\u00e9es collect\u00e9es depuis 2009 par le t\u00e9lescope spatial Kepler, ce documentaire interroge la possibilit\u00e9 d'une vie extraterrestre dans notre galaxie. Notre galaxie, la Voie lact\u00e9e, comporte entre 200 et 300 milliards d'\u00e9toiles. Bon nombre d'entre elles ont dans leur orbite des plan\u00e8tes\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/07\/telescope-kepler.jpg?fit=800%2C600&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/07\/telescope-kepler.jpg?fit=800%2C600&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/07\/telescope-kepler.jpg?fit=800%2C600&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/07\/telescope-kepler.jpg?fit=800%2C600&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2496,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-planete-a-latmosphere-de-pierre\/","url_meta":{"origin":8563,"position":4},"title":"La plan\u00e8te \u00e0 l\u2019atmosph\u00e8re de pierre","author":"Admin","date":"10 mars 2015","format":false,"excerpt":"Dans le th\u00e8me des exoplan\u00e8tes, voil\u00e0 une d\u00e9couverte qui vient de d\u00e9montrer que nous avons encore beaucoup de chemins \u00e0 parcourir avant de tout savoir. L\u2019exoplan\u00e8te Kepler 7-b, d\u00e9couverte en janvier 2010 dans la constellation de la Lyre, aurait une atmosph\u00e8re min\u00e9rale. Une bizarrerie jamais vue parmi les exoplan\u00e8tes.","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/wordpress\/wp-content\/uploads\/2015\/03\/laterredufutur.com_photos_kepler-7-B-1.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":2400,"url":"https:\/\/www.laterredufutur.com\/accueil\/kepler-detecte-deux-planetes-presque-identiques-a-la-terre\/","url_meta":{"origin":8563,"position":5},"title":"Kepler d\u00e9tecte deux plan\u00e8tes presque identiques \u00e0 la Terre","author":"Admin","date":"6 janvier 2015","format":false,"excerpt":"Taille: comparable \u00e0 la Terre. Composition: sans doute rocheuse. Temp\u00e9rature: agr\u00e9able. Mardi 6 janvier 2014, des scientifiques ont annonc\u00e9 la d\u00e9couverte de deux plan\u00e8tes lointaines qui semblent \u00eatre d'excellentes candidates pour offrir des conditions propices \u00e0 la vie. La premi\u00e8re serait m\u00eame la plan\u00e8te la plus semblable \u00e0 la Terre\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"kepler","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2011\/12\/kepler-0.jpg?fit=494%2C351&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/8563","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/comments?post=8563"}],"version-history":[{"count":1,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/8563\/revisions"}],"predecessor-version":[{"id":8565,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/8563\/revisions\/8565"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/1612"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=8563"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=8563"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=8563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}