{"id":931,"date":"2004-11-15T14:32:00","date_gmt":"2004-11-15T13:32:00","guid":{"rendered":"https:\/\/kids.esa.int\/dwarfs_and_supergiants\/"},"modified":"2026-10-08T00:33:54","modified_gmt":"2026-10-07T22:33:54","slug":"dwarfs_and_supergiants","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/dwarfs_and_supergiants\/","title":{"rendered":"K\u00e4\u00e4pi\u00f6t ja superj\u00e4ttil\u00e4iset"},"content":{"rendered":"
\n

Aurinko on t\u00e4hti. Kuten useimmat t\u00e4hdet, Aurinko on eritt\u00e4in kuuma kaasupallo, joka s\u00e4teilee valtavia m\u00e4\u00e4ri\u00e4 valoa, l\u00e4mp\u00f6\u00e4 ja muuta s\u00e4teily\u00e4. T\u00e4m\u00e4 s\u00e4teily syntyy ytimess\u00e4 tapahtuvien ydinreaktioiden seurauksena. Se on kuin miljoonat vetypommit r\u00e4j\u00e4ht\u00e4isiv\u00e4t joka sekunti.<\/p>\n<\/div>\n

T\u00e4hti\u00e4 on monenlaisia. Punaiset t\u00e4hdet ovat viileimpi\u00e4, ja niiden pintal\u00e4mp\u00f6tila on noin 2500 celsiusastetta. Sinivalkoiset t\u00e4hdet ovat kuumimpia, ja niiden l\u00e4mp\u00f6tila nousee huikeaan
40 000 astetta. Auringon kaltaiset keltaiset t\u00e4hdet sijoittuvat n\u00e4iden v\u00e4lille, ja niiden pintal\u00e4mp\u00f6tila on noin 5 500 astetta.<\/p>\n

T\u00e4hti\u00e4 on monen kokoisia. Aurinko on keskikokoinen. Se kuluttaa vetypolttoaineensa melko hitaasti, joten se voi loistaa jopa 10 miljardia vuotta. Jotkut t\u00e4hdet ovat paljon suurempia ja kuumempia kuin Aurinko. Punainen superj\u00e4ttil\u00e4inen Antares on 800 kertaa laajempi kuin Aurinko. Jos se sijaitsisi aurinkokuntamme keskell\u00e4, se nielaisi kaikki sisemm\u00e4t planeetat, Maa mukaan lukien. Kuten paljon polttoainetta kuluttavat autot, n\u00e4m\u00e4 superj\u00e4ttil\u00e4iset kuluttavat koko vety- ja heliumpolttoaineensa hyvin nopeasti. Noin 500 miljoonan vuoden kuluttua ne kuolevat supernovar\u00e4j\u00e4hdyksess\u00e4.<\/p>\n

Kylmimm\u00e4t ja hitaimmin palavat t\u00e4hdet ovat punaisia k\u00e4\u00e4pi\u00f6it\u00e4. Ne voivat el\u00e4\u00e4 yli 10 biljoonaa (10 000 miljardia) vuotta. Viel\u00e4 viile\u00e4mpi\u00e4 ja pienempi\u00e4 ovat ruskeat k\u00e4\u00e4pi\u00f6t. Ne ovat \u2018ep\u00e4onnistuneita t\u00e4hti\u00e4\u2019. Ne ovat niin viileit\u00e4 \u2013 joskus vain muutaman sadan asteen l\u00e4mp\u00f6isi\u00e4 pinnaltaan \u2013 ett\u00e4 niiden ydinreaktiot eiv\u00e4t koskaan k\u00e4ynnisty.<\/p>","protected":false},"excerpt":{"rendered":"

The Sun is a star. Like most stars, the Sun is a ball of very hot gas that gives off huge amounts of light, heat and other radiation. This radiation […]<\/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\/2000\/09\/the_tycho_supernova2\/17865860-3-eng-GB\/The_Tycho_supernova.jpg","esa_banner_description":"The Tycho supernova","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2000\/09\/The_Tycho_supernova2","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-931","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\/fi\/wp-json\/wp\/v2\/posts\/931","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/comments?post=931"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/931\/revisions"}],"predecessor-version":[{"id":2074,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/931\/revisions\/2074"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=931"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=931"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=931"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=931"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=931"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=931"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=931"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}