{"id":978,"date":"2004-11-15T14:43:00","date_gmt":"2004-11-15T13:43:00","guid":{"rendered":"https:\/\/kids.esa.int\/star_death\/"},"modified":"2026-10-08T00:34:26","modified_gmt":"2026-10-07T22:34:26","slug":"star_death","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/star_death\/","title":{"rendered":"Mort d'une \u00e9toile"},"content":{"rendered":"
\n

La plupart des \u00e9toiles mettent des millions d'ann\u00e9es \u00e0 mourir. Lorsqu'une \u00e9toile comme le Soleil a \u00e9puis\u00e9 tout son hydrog\u00e8ne, elle se dilate pour devenir une g\u00e9ante rouge. Celle-ci peut atteindre plusieurs millions de kilom\u00e8tres de diam\u00e8tre, soit une taille suffisante pour engloutir les plan\u00e8tes Mercure et V\u00e9nus.<\/p>\n<\/div>\n

Apr\u00e8s avoir d\u00e9sagr\u00e9g\u00e9 ses couches ext\u00e9rieures, l'\u00e9toile se concentre pour devenir une naine blanche tr\u00e8s dense. Une simple cuiller \u00e0 caf\u00e9 de mati\u00e8re d'une naine blanche pourrait peser jusqu'\u00e0 100 tonnes. Sur une p\u00e9riode de plusieurs milliards d\u2019ann\u00e9es, la naine blanche se refroidit et devient invisible.<\/p>\n

Les \u00e9toiles dont la masse est huit fois sup\u00e9rieure \u00e0 celle du Soleil finissent leur vie tr\u00e8s brutalement. Lorsqu'elles n\u2019ont plus de carburant, elles se transforment en super g\u00e9antes rouges. Elles essaient de rester en vie en br\u00fblant diff\u00e9rents types de carburants, mais cela ne marche que pendant quelques millions d\u2019ann\u00e9es seulement. Puis elles \u00e9clatent dans une \u00e9norme explosion en supernova.<\/p>\n

Pendant environ une semaine, la supernova d\u00e9passe en brillance toutes les autres \u00e9toiles de sa galaxie. Puis elle s'affaiblit rapidement. Il ne reste plus qu'un objet minuscule et dense, une \u00e9toile \u00e0 neutrons ou un trou noir, entour\u00e9 d'un nuage de gaz tr\u00e8s chaud en expansion.<\/p>\n

Les \u00e9l\u00e9ments qui composent la super g\u00e9ante (comme l'oxyg\u00e8ne, le carbone et le fer) sont \u00e9parpill\u00e9s dans l'espace. Cette poussi\u00e8re d'\u00e9toile peut \u00e9ventuellement donner naissance \u00e0 d'autres \u00e9toiles et \u00e0 d'autres plan\u00e8tes.<\/p>","protected":false},"excerpt":{"rendered":"

Most stars take millions of years to die. When a star like the Sun has burned all of its hydrogen fuel, it expands to become a red giant. This may […]<\/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\/2003\/05\/ngc_6369_a_cosmic_ghost2\/17884213-2-eng-GB\/NGC_6369_a_cosmic_ghost.jpg","esa_banner_description":"NGC 6369, a cosmic ghost","esa_banner_credit":"NASA and The Hubble Heritage Team (STScI\/AURA)","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2003\/05\/NGC_6369_a_cosmic_ghost2","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":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-978","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-stars-and-galaxies","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/978","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=978"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/978\/revisions"}],"predecessor-version":[{"id":2121,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/978\/revisions\/2121"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=978"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=978"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=978"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=978"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=978"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=978"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=978"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}