{"id":196,"date":"2021-12-02T12:44:26","date_gmt":"2021-12-02T11:44:26","guid":{"rendered":"https:\/\/kids.esa.int\/stars2\/"},"modified":"2026-10-08T00:25:22","modified_gmt":"2026-10-07T22:25:22","slug":"stars2","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/stars2\/","title":{"rendered":"\u00c9toiles"},"content":{"rendered":"
\n

Tout comme les \u00eatres humains, les \u00e9toiles naissent, vieillissent et meurent. Elles naissent dans d\u2019immenses nuages froids de gaz et de poussi\u00e8re, appel\u00e9s \u2018 n\u00e9buleuses \u2019. La plus c\u00e9l\u00e8bre d\u2019entre elles est la n\u00e9buleuse d\u2019Orion, visible \u00e0 l\u2019\u0153il nu.<\/p>\n<\/div>\n

Des milliards d'ann\u00e9es apr\u00e8s sa naissance, lorsqu'une \u00e9toile de taille moyenne comme le Soleil arrive en fin de vie, elle gonfle pour devenir une g\u00e9ante rouge. Son diam\u00e8tre peut alors atteindre plusieurs millions de kilom\u00e8tres : lorsque cela arrivera au Soleil, il sera assez grand pour engloutir les plan\u00e8tes Mercure et V\u00e9nus !<\/p>\n

Apr\u00e8s avoir expuls\u00e9 ses couches externes de gaz, l\u2019\u00e9toile s\u2019effondre pour former une naine blanche extr\u00eamement dense. Une cuill\u00e8re \u00e0 caf\u00e9 de mati\u00e8re provenant d\u2019une naine blanche p\u00e8serait jusqu\u2019\u00e0 100 tonnes ! Au fil de milliards d'ann\u00e9es, la naine blanche se refroidit et devient invisible. Mais ne t'inqui\u00e8te pas, cela n'arrivera pas \u00e0 notre Soleil avant environ 5 milliards d'ann\u00e9es !<\/p>\n

Les petites \u00e9toiles ont une longue dur\u00e9e de vie, sup\u00e9rieure \u00e0 10 milliards d'ann\u00e9es. On n'a jamais observ\u00e9 leur mort, mais on pense qu'elles finissent leurs jours tranquillement avant de s'\u00e9teindre peu \u00e0 peu.<\/p>\n

\"Supernova
Vestige de supernova<\/figcaption><\/figure>\n

Les \u00e9toiles les plus massives mettent fin \u00e0 leur vie de mani\u00e8re tr\u00e8s soudaine. Vers la fin de leur existence, elles gonflent pour devenir des superg\u00e9antes rouges, avant de finir par exploser dans une gigantesque 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 form\u00e9s \u00e0 l'int\u00e9rieur de la superg\u00e9ante (tels que l'oxyg\u00e8ne, le carbone et le fer) sont dispers\u00e9s dans l'espace. Cette poussi\u00e8re d'\u00e9toiles finira par donner naissance \u00e0 d'autres \u00e9toiles et plan\u00e8tes !<\/p>","protected":false},"excerpt":{"rendered":"

Like people, stars are born, they grow old and they die. Their birth places are huge, cold clouds of gas and dust, known as ‘nebulas’. The most famous of these […]<\/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\/2004\/01\/nearby_galaxy_ngc_1569_is_a_hotbed_of_star_birth_activity2\/17880180-2-eng-GB\/Nearby_galaxy_NGC_1569_is_a_hotbed_of_star_birth_activity.jpg","esa_banner_description":"Nearby galaxy NGC 1569 is a 'hotbed' of star birth activity","esa_banner_credit":"ESA, NASA and Peter Anders (G\u00f6ttingen University Galaxy Evolution Group, Germany)","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2004\/01\/Nearby_galaxy_NGC_1569_is_a_hotbed_of_star_birth_activity2","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-196","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\/196","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=196"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/196\/revisions"}],"predecessor-version":[{"id":4352,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/196\/revisions\/4352"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=196"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=196"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=196"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=196"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=196"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=196"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=196"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=196"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=196"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=196"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}