{"id":67355,"date":"2020-08-11T08:46:24","date_gmt":"2020-08-11T05:46:24","guid":{"rendered":"http:\/\/realitatearutiera.ro\/?p=67355"},"modified":"2020-08-11T08:46:27","modified_gmt":"2020-08-11T05:46:27","slug":"dintii-si-oasele-tale-contin-praf-de-stele","status":"publish","type":"post","link":"https:\/\/realitatearutiera.ro\/?p=67355","title":{"rendered":"Din\u021bii \u0219i oasele tale con\u021bin praf de stele"},"content":{"rendered":"\n<p>Din\u021bii \u0219i oasele tale con\u021bin praf de stele.<\/p>\n\n\n\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/video-images.vice.com\/\/articles\/5f2d10c477331c009d1fe8a0\/lede\/1596789900734-2019ehk-amgfinal.png?resize=251%2C251&#038;ssl=1\" alt=\"Calciul din corpul t\u0103u a fost produs de explozii stelare\" width=\"251\" height=\"251\" data-recalc-dims=\"1\" \/><\/figure>\n\n\n\n<p>Suntem f\u0103cu\u021bi din \u201dpraf de stele\u201d, a zis astronomul Carl Sagan la \u00eenceputul anil 1980 \u00eentr-o serie televizat\u0103 despre cosmos, \u00een care vorbea despre cum corpurile noastre sunt create din elemente g\u0103site \u00een nucleul stelelor. Oamenii de \u0219tiin\u021b\u0103 nu doar c\u0103, datorit\u0103 unui\u00a0<a href=\"https:\/\/arxiv.org\/abs\/2005.01782\">studiu<\/a>, confirm\u0103 cuvintele lui Sagan, ci au \u0219i observat felul \u00een care stelele explodeaz\u0103 \u0219i-\u0219i dau mai departe praful \u00een univers.<\/p>\n\n\n\n<p>Se pare c\u0103 jum\u0103tate din tot calciul din univers &#8211; chiar \u0219i cel din din\u021bii \u0219i oasele noastre &#8211; a fost creat de stele moarte. \u00cen urma exploziilor stelare, supernove, \u00ee\u0219i \u00eempr\u0103\u0219tie mineralele \u00een univers \u00een cantit\u0103\u021bi enorme. De\u0219i se \u0219tia c\u0103 exploziile \u0219i fuziunile \u00eentre stele creeaz\u0103 elemente ca aurul \u0219i platina, crearea calciului era un mister. Exploziile astea stelare &#8211; numite \u201esupernove bogate \u00een calciu\u201d &#8211; sunt evenimente extrem de rare pe care oamenii de \u0219tiin\u021b\u0103 le v\u00e2neaz\u0103 de ceva timp. De aceea originea acestei supernove \u0219i mecanismul de formare a calciului au r\u0103mas un mister pentru decenii \u00eentregi.<a href=\"https:\/\/www.vice.com\/ro\/section\/tech\">Tech<\/a><\/p>\n\n\n\n<p>P\u00e2n\u0103 acum. \u00cen studiul, publicat \u00een&nbsp;<em>The Astrophysical Journal<\/em>&nbsp;pe 5 august, oamenii de \u0219tiin\u021b\u0103 examineaz\u0103 \u00een sf\u00e2r\u0219it o supernova bogat\u0103 \u00een calciu cu ajutorul razelor X.<\/p>\n\n\n\n<p>\u00cen aprilie 2019, un astronom amator a observat o lumin\u0103 puternic\u0103 \u00een timp ce analiza stelele. Iar a doua zi a sesizat un punct portocaliu luminos \u00een acela\u0219i loc, care nu existase anterior. A oferit aceast\u0103 informa\u021bie comunit\u0103\u021bii astronomice locale, iar ve\u0219tile unei posibile supernova s-au r\u0103sp\u00e2ndit rapid. S-a format o echip\u0103 global\u0103 de aproape 70 de oameni de \u0219tiin\u021b\u0103 ca s\u0103 observe steaua \u00een ac\u021biune.<\/p>\n\n\n\n<p>Se pare c\u0103 ei au observat o supernova bogat\u0103 \u00een calciul la zece ore dup\u0103 explozie. Acest eveniment a oferit o \u0219ans\u0103 f\u0103r\u0103 precedent de a analiza via\u021ba unei stele \u0219i explozia sa.<\/p>\n\n\n\n<p>De\u0219i stelele creeaz\u0103 cantit\u0103\u021bi mici de calciu prin arderea heliului de-a lungul vie\u021bii lor, supernovele bogate \u00een calciu produc cantit\u0103\u021bi enorme \u00een c\u00e2teva secunde.<\/p>\n\n\n\n<p>Noile descoperiri au scos la iveal\u0103 c\u0103 o supernova bogat\u0103 \u00een calciu e o stea compact\u0103 care eman\u0103 un strat de gaz \u00een ultimele etape ale vie\u021bii sale. C\u00e2nd explodeaz\u0103, materia sa se ciocne\u0219te de materialul din exterior \u0219i emite raze X luminoase. Explozia produce temperaturi extrem de ridicate \u0219i presiune ridicat\u0103, ceea ce duce la o reac\u021bie chimic\u0103 din care rezult\u0103 calciul pe care-l cunoa\u0219tem.<a href=\"https:\/\/www.vice.com\/ro\/section\/high-hui\">High Hui<\/a><\/p>\n\n\n\n<p>\u201eEvenimentele astea sunt at\u00e2t de rare \u00eenc\u00e2t nu \u0219tiam ce producea supernovele bogate \u00een calciu\u201d, a&nbsp;<a href=\"https:\/\/phys.org\/news\/2020-08-calcium-rich-supernova-x-rays.html\">declarat<\/a>&nbsp;Wynn Jacobson-Gal\u00e1n, un absolvent al universit\u0103\u021bii Northwestern care a condus studiul. \u201ePrin observarea activit\u0103\u021bii stelei \u00een ultima lun\u0103 de via\u021b\u0103, am avut acces la o zon\u0103 care nu mai fusese explorat\u0103, ceea ce ne-a oferit noi domenii de studiu \u00een \u0219tiin\u021ba fenomenelor tranzitorii\u201d. \u00cen aceast\u0103 lume, au zis cercet\u0103torii, trebuie s\u0103 descopere lucrurile rapid \u00eenainte s\u0103 dispar\u0103.<\/p>\n\n\n\n<p>Descoperirile lor sugereaz\u0103 c\u0103 stelele responsabile de exploziile astea trec cel mai probabil printr-un soi de instabilitate. Cercet\u0103torii lucreaz\u0103 la o continuare a studiului care include felul \u00een care supernova evolueaz\u0103 dup\u0103 explozie.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Din\u021bii \u0219i oasele tale con\u021bin praf de stele. Suntem f\u0103cu\u021bi din \u201dpraf de stele\u201d, a zis astronomul Carl Sagan la<\/p>\n","protected":false},"author":1,"featured_media":67356,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":""},"categories":[6],"tags":[],"class_list":["post-67355","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-social"],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/realitatearutiera.ro\/wp-content\/uploads\/2020\/08\/200px-Calcium_1.jpg?fit=200%2C273&ssl=1","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p61naM-hwn","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/posts\/67355","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=67355"}],"version-history":[{"count":1,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/posts\/67355\/revisions"}],"predecessor-version":[{"id":67357,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/posts\/67355\/revisions\/67357"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=\/wp\/v2\/media\/67356"}],"wp:attachment":[{"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=67355"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=67355"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/realitatearutiera.ro\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=67355"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}