{"id":881,"date":"2006-09-07T12:06:00","date_gmt":"2006-09-07T10:06:00","guid":{"rendered":"https:\/\/kids.esa.int\/supernovas\/"},"modified":"2026-10-08T00:33:19","modified_gmt":"2026-10-07T22:33:19","slug":"supernovas","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/supernovas\/","title":{"rendered":"Explosions d\u2019\u00e9toiles"},"content":{"rendered":"
\n

Il arrive de temps \u00e0 autre que notre galaxie, la Voie lact\u00e9e, soit illumin\u00e9e par une gigantesque explosion. Connu sous le nom de supernova, ce ph\u00e9nom\u00e8ne d'une extr\u00eame violence signe la mort d'une super g\u00e9ante \u2013 une \u00e9toile beaucoup plus grosse que le Soleil. L\u2019une des derni\u00e8res supernovas dans la Voie Lact\u00e9e s\u2019est produite il y a environ 340 ann\u00e9es, dans la constellation de Cassiop\u00e9e, ce qui lui a valu le nom de Cassiop\u00e9e A (Cas A).<\/p>\n<\/div>\n

Cas A se situe \u00e0 dix mille ann\u00e9es-lumi\u00e8re de la Terre. Les observatoires, comme le t\u00e9lescope spatial Hubble de l\u2019ESA et de la NASA, ont effectu\u00e9 des \u00e9tudes pouss\u00e9es sur le nuage de gaz et de poussi\u00e8re qui continue de luire.<\/p>\n

\"Zooming
Zoom sur Cassiop\u00e9e A<\/figcaption><\/figure>\n

Les images montrent un anneau de mati\u00e8re d\u00e9chiquet\u00e9 qui s\u2019\u00e9loigne rapidement du lieu de l\u2019explosion. Une partie de cette mati\u00e8re se d\u00e9place \u00e0 pr\u00e8s de 50 millions de km \u00e0 l'heure (une vitesse qui permettrait de relier la Terre \u00e0 la Lune en 30 secondes). Les \u00e9normes tourbillons de d\u00e9bris luisent car ils ont \u00e9t\u00e9 chauff\u00e9s par l'onde de choc de la supernova au moment de son passage.<\/p>\n

Il existe plusieurs types d\u2019explosions de supernova. Cas A a explos\u00e9 lorsqu\u2019une petite \u00e9toile, appel\u00e9e une naine blanche, a capt\u00e9 une grande quantit\u00e9 de mati\u00e8re d\u2019une \u00e9toile proche. Au fur et \u00e0 mesure que la quantit\u00e9 de gaz augmentait, la naine blanche est devenue si chaude et active qu\u2019elle a fini par exploser. D\u2019autres supernovas se produisent lorsque des \u00e9toiles de tr\u00e8s grande masse viennent \u00e0 \u00e9puisement de leur carburant nucl\u00e9aire. Incapables de continuer \u00e0 lib\u00e9rer de l\u2019\u00e9nergie, leur c\u0153ur s\u2019effondre, d\u00e9truisant l\u2019\u00e9toile.<\/p>\n

Les supernovas sont importantes car elles r\u00e9pandent de la mati\u00e8re d\u2019\u00e9toile \u00e0 travers la galaxie. Presque tout sur Terre (y compris nous !) est fait \u00e0 partir d\u2019\u00e9l\u00e9ments (comme le carbone et le fer) issus de ces poussi\u00e8res d\u2019\u00e9toiles.<\/p>","protected":false},"excerpt":{"rendered":"

Every now and again our Milky Way galaxy is lit up by a huge explosion. Known as a supernova, this violent event marks the death of a supergiant \u2013 a […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2006\/08\/hubble_s_view_of_supernova_explosion_cassiopeia_a2\/18245292-2-eng-GB\/Hubble_s_view_of_supernova_explosion_Cassiopeia_A.jpg","esa_banner_description":"Hubble\u2019s view of supernova explosion Cassiopeia A","esa_banner_credit":"NASA, ESA, and the Hubble Heritage (STScI\/AURA)-ESA\/Hubble Collaboration","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2006\/08\/Hubble_s_view_of_supernova_explosion_Cassiopeia_A2","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[10,11,21],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-881","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-stars-and-galaxies"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/881","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/comments?post=881"}],"version-history":[{"count":5,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/881\/revisions"}],"predecessor-version":[{"id":4717,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/881\/revisions\/4717"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=881"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=881"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=881"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=881"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=881"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=881"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=881"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=881"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=881"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=881"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}