{"id":6402,"date":"2019-04-01T13:25:42","date_gmt":"2019-04-01T13:25:42","guid":{"rendered":"http:\/\/www.phys.uaic.ro\/?page_id=6402"},"modified":"2019-04-17T10:02:53","modified_gmt":"2019-04-17T10:02:53","slug":"praf-de-stele","status":"publish","type":"page","link":"https:\/\/www.phys.uaic.ro\/old\/index.php\/cercetare\/articole-explicate-pe-inetelesul-tuturor\/praf-de-stele\/","title":{"rendered":"Din praf de stele se nasc planete"},"content":{"rendered":"<div class=\"colorbox\" style=\"background-color: #e6e6e6;\">\n<p>\u00cen timpul vie\u021bii, stelele produc elementele chimice u\u0219oare, transform\u00e2nd r\u00e2nd pe r\u00e2nd hidrogenul \u00een heliu, heliul \u00een beriliu, beriliul \u00een carbon \u0219i oxigen. \u00cen momentul \u00een care \u00een inima stelei se acumuleaz\u0103 fierul, stelele se \u00eendreapt\u0103 repede c\u0103tre finalul vie\u021bii. Sf\u00e2r\u0219esc violent printr-o explozie uria\u0219\u0103 (supernov\u0103) \u0219i doar \u00eentr-o frac\u021biune de secund\u0103 se produc elementele grele precum aurul sau platina, p\u00e2n\u0103 la uraniu. Al\u0103turi de ace\u0219ti atomi, spa\u021biul interstelar imens con\u021bine un amestec de gaze moleculare \u0219i praf interstelar, macromolecule cu structur\u0103 mixt\u0103 aromatic-alifatic\u0103 construite pe un schelet de carbon sau siliciu. To\u021bi ace\u0219ti compu\u0219i care formeaz\u0103 generic praful interstelar, nu pot fi crea\u021bi la temperaturile \u0219i presiunile foarte ridicate din interiorul stelelor.<br \/>\nAtomii simpli c\u00e2t \u0219i compu\u0219ii moleculari complec\u0219i vor contribui la formarea viitoarelor genera\u021bii de stele sau planete. Modalitatea de formare a prafului interstelar nu este cunoscut\u0103 \u00eenc\u0103, dar una din posibilit\u0103\u021bi presupune c\u0103 doar stelele gigante ro\u0219ii pot s\u0103-l genereze \u00een timpul fazei de expansiune \u0219i expulzare a straturilor exterioare c\u0103tre mediul interstelar.<\/p>\n<p>Pentru a face un pas suplimentar c\u0103tre \u00een\u021belegerea structurii \u0219i compozi\u021biei prafului interstelar, un colectiv de studen\u021bi, cercet\u0103tori \u0219i profesori de la Facultatea de Fizic\u0103, Universitatea Alexandru Ioan Cuza din Ia\u0219i au produs un praf analog, \u00een condi\u021bii de laborator. Au folosit molecule disponibile \u00een mediul interstelar, precum metanul, care supuse ac\u021biunii unei desc\u0103rc\u0103ri electrice \u00een heliu, se descompun \u0219i se reformeaz\u0103 \u00een mod continuu. \u00cen urma acestui proces s-a ob\u021binut un praf alifatic, cu schelet de carbon, analog prafului interstelar din anumite regiuni ale spa\u021biului. Este un proces de durat\u0103 \u0219i \u00eentr-o zi de func\u021bionare continu\u0103 a instala\u021biei de plasm\u0103, se produc doar c\u00e2teva miligrame de praf. La scala de timp de miliarde de ani a unei galaxii, reprezint\u0103 doar o frac\u021biune de secund\u0103 ce poate explica modul de formare c\u00e2t \u0219i abunden\u021ba prafului interstelar.<\/p>\n<p><img decoding=\"async\" style=\"padding: 0 0 0 0;\" src=\"http:\/\/www.phys.uaic.ro\/wp\/cercetare\/articole-explicate\/praf-de-stele\/praf-de-stele-1-2-3-200.jpg\" alt=\"praf-de-stele-1-2-3\" \/><\/p>\n<p><img decoding=\"async\" style=\"padding: 0 0 0 0;\" src=\"http:\/\/www.phys.uaic.ro\/wp\/cercetare\/articole-explicate\/praf-de-stele\/praf-de-stele-4-5-250.jpg\" alt=\"praf-de-stele-4-5\" \/><\/p>\n<p>Detalii suplimentare:<\/p>\n<ul>\n<li>la <a href=\"http:\/\/www.uaic.ro\/prafdestele\/\">http:\/\/www.uaic.ro\/prafdestele\/<\/a><\/li>\n<li>\u00een articolul publicat de <b>Oxford Academic Press<\/b>:\n<ul style=\"list-style-type: none;\">\n<li>Hodoroaba, B., Gerber, I. C., Ciubotaru, D., Mihaila, I., Dobromir, M., Pohoata, V., &amp; Topala, I. \u2013 <a href=\"https:\/\/doi.org\/10.1093\/mnras\/sty2497\"><b>Carbon fluffy aggregates produced by helium \u2013 hydrocarbon high pressure plasmas as analogs to interstellar dust<\/b><\/a>, <i>Monthly Notices of the Royal Astronomical Society<\/i>, Volumul 481, Numarul 2, Paginile 2841\u20132850, 1 Decembrie 20180<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u00cen timpul vie\u021bii, stelele produc elementele chimice u\u0219oare, transform\u00e2nd r\u00e2nd pe r\u00e2nd hidrogenul \u00een heliu, heliul \u00een beriliu, beriliul \u00een carbon \u0219i oxigen. \u00cen momentul \u00een care \u00een inima stelei se acumuleaz\u0103 fierul, stelele se \u00eendreapt\u0103 repede c\u0103tre finalul vie\u021bii. Sf\u00e2r\u0219esc violent printr-o explozie uria\u0219\u0103 (supernov\u0103) \u0219i doar \u00eentr-o frac\u021biune de secund\u0103 se produc elementele grele precum aurul\u2026 <span class=\"read-more\"><a href=\"https:\/\/www.phys.uaic.ro\/old\/index.php\/cercetare\/articole-explicate-pe-inetelesul-tuturor\/praf-de-stele\/\">Read More &raquo;<\/a><\/span><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":6398,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-6402","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/pages\/6402","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/comments?post=6402"}],"version-history":[{"count":0,"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/pages\/6402\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/pages\/6398"}],"wp:attachment":[{"href":"https:\/\/www.phys.uaic.ro\/old\/index.php\/wp-json\/wp\/v2\/media?parent=6402"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}