Anakol y\u0131ld\u0131zlar\u0131 k\u00fctlelerine g\u00f6re (G\u00fcne\u015f\u2019in k\u00fctlesini \u201c1\u201d olarak al\u0131yoruz) s\u0131n\u0131fland\u0131r\u0131ld\u0131klar\u0131nda, en a\u011f\u0131rdan en hafife do\u011fru; O, B, A, F, G, K ve M harfleriyle sembolize edilirler. Bu harfler, anakol y\u0131ld\u0131z\u0131n\u0131n k\u00fctlesini ve ayn\u0131 zamanda tayf t\u00fcr\u00fcn\u00fc sembolize eder.<\/p>\n
Y\u0131ld\u0131z\u0131n do\u011fum an\u0131ndaki k\u00fctlesine g\u00f6re, anakol evresinin s\u00fcresi de\u011fi\u015fiklik g\u00f6sterse de, \u00f6n\u00fcnde sonunda gen\u00e7lik g\u00fcnleri sona eren y\u0131ld\u0131z\u0131m\u0131z de\u011fi\u015fmeye ve farkl\u0131 t\u00fcrlere evrimle\u015fece\u011fi bir s\u00fcrece girmeye ba\u015flar.<\/p>\n
Genel kural \u015fudur; y\u0131ld\u0131z\u0131n k\u00fctlesi (k\u00fctleyi ayn\u0131 \u015fey olmasa da a\u011f\u0131rl\u0131k olarak d\u00fc\u015f\u00fcnebilirsiniz) ne kadar k\u00fc\u00e7\u00fckse o kadar uzun ya\u015far. \u015eimdi, tek tek belli ba\u015fl\u0131 y\u0131ld\u0131z t\u00fcrlerine g\u00f6z atal\u0131m:<\/p>\n
G\u00fcne\u015f\u2019in %7.5\u2019i ile %60\u2019\u0131 aras\u0131nda bir k\u00fctleye sahip olan M tayf s\u0131n\u0131f\u0131 k\u0131rm\u0131z\u0131 c\u00fcce y\u0131ld\u0131zlar\u0131n anakol evresinde ge\u00e7irdikleri s\u00fcre; k\u00fctlelerine g\u00f6re 70 milyar y\u0131l ila birka\u00e7 trilyon y\u0131l aras\u0131nda de\u011fi\u015fir. K\u00fctlesi en y\u00fcksek olanlar\u0131 \u00f6m\u00fcrlerinin sonunda bir beyaz c\u00fcceye d\u00f6n\u00fc\u015ferek \u00f6l\u00fcrler. Daha d\u00fc\u015f\u00fck k\u00fctleli M tipi c\u00fcceler ise, yava\u015f\u00e7a s\u00f6nerek bir kara c\u00fcceye d\u00f6n\u00fc\u015fecektir.<\/p>\n
13.8 milyar ya\u015f\u0131ndaki evrende, \u015fimdiye kadar hi\u00e7bir k\u0131rm\u0131z\u0131 c\u00fcce y\u0131ld\u0131z anakol evresinden \u00e7\u0131k\u0131p kara c\u00fcceye d\u00f6n\u00fc\u015ferek \u00f6lmemi\u015ftir.<\/p>\n
K\u0131rm\u0131z\u0131 c\u00fcce y\u0131ld\u0131zlar, evrende say\u0131ca en fazla bulunan y\u0131ld\u0131zlard\u0131r ve t\u00fcm y\u0131ld\u0131zlar\u0131n y\u00fczde 80\u2019ini olu\u015ftururlar.<\/p>\n
G\u00fcne\u015f\u2019in %60\u2019\u0131 ila %85\u2019i kadar k\u00fctleye sahip olan K tayf s\u0131n\u0131f\u0131 turuncu c\u00fcce y\u0131ld\u0131zlar, k\u00fctle miktarlar\u0131na g\u00f6re 20-60 milyar y\u0131l aras\u0131 bir s\u00fcreyi anakol evresinde ge\u00e7irirler. Bu s\u00fcrenin sonuda, \u00f6nce bir k\u0131rm\u0131z\u0131 dev y\u0131ld\u0131za, ard\u0131ndan bir gezegenimsi bulutsu olu\u015fturarak beyaz c\u00fcceye d\u00f6n\u00fc\u015f\u00fcp \u00f6l\u00fcrler.<\/p>\n
Evrenin 13.8 milyar y\u0131ll\u0131k ya\u015f\u0131 s\u00fcresince, bug\u00fcne kadar hi\u00e7bir K s\u0131n\u0131f\u0131 anakol y\u0131ld\u0131z\u0131 k\u0131rm\u0131z\u0131 deve d\u00f6n\u00fc\u015fecek kadar ya\u015flanmam\u0131\u015f ve \u00f6lmemi\u015ftir.<\/p>\n
Turuncu c\u00fcce y\u0131ld\u0131zlar, evrende var olan t\u00fcm y\u0131ld\u0131zlar\u0131n yakla\u015f\u0131k y\u00fczde 8\u2019ini olu\u015ftururlar.<\/p>\n
G\u00fcne\u015f\u2019in k\u00fctlesinin %85\u2019i ila, 1.1 kat\u0131 aras\u0131nda k\u00fctleye sahip olan G tayf tipi sar\u0131 y\u0131ld\u0131zlar, k\u00fctlelerine g\u00f6re 8 ila 13-15 milyar y\u0131l aras\u0131nda anakol evresinde kal\u0131rlar. Sonras\u0131nda k\u0131rm\u0131z\u0131 deve d\u00f6n\u00fc\u015fler. Sonunda bir gezegenimsi bulutsu olu\u015fturup, beyaz c\u00fcceye evrilerek hayatlar\u0131 son bulur.<\/p>\n
Evren var oldu\u011fundan bug\u00fcne kadar olu\u015fan G\u00fcne\u015f benzeri y\u0131ld\u0131zlar\u0131n yar\u0131ya yak\u0131n\u0131 ya \u015fu an k\u0131rm\u0131z\u0131 deve d\u00f6n\u00fc\u015fm\u00fc\u015f, ya da ge\u00e7mi\u015fte beyaz c\u00fcceye d\u00f6n\u00fc\u015ferek \u00f6lm\u00fc\u015ft\u00fcr.<\/p>\n
G tayf s\u0131n\u0131f\u0131 y\u0131ld\u0131zlar, evrende var olan y\u0131ld\u0131zlar\u0131n say\u0131ca yakla\u015f\u0131k y\u00fczde 3.5\u2019ini meydana getirirler.<\/p>\n
G\u00fcne\u015f\u2019in 1.5\u2019i ila 2.5\u2019i aras\u0131nda k\u00fctleye sahip olan A ve F tayf tipi y\u0131ld\u0131zlar\u0131n anakol evresi, k\u00fctle miktar\u0131ndaki de\u011fi\u015fime g\u00f6re yakla\u015f\u0131k 300 milyon y\u0131l ile d\u00f6rt milyar y\u0131l aras\u0131nda bir s\u00fcreci kapsar. Bu s\u00fcre sonunda y\u0131ld\u0131z bir k\u0131rm\u0131z\u0131 deve d\u00f6n\u00fc\u015f\u00fcr. Ard\u0131ndan \u00f6nce gezegenimsi bulutsu ve nihayetinde bir beyaz c\u00fcceye d\u00f6n\u00fc\u015ferek \u00f6l\u00fcr. Bug\u00fcn var olan k\u0131rm\u0131z\u0131 dev y\u0131ld\u0131zlar ile, beyaz c\u00fccelerin \u00e7ok b\u00fcy\u00fck bir k\u0131sm\u0131 A ve F tipi y\u0131ld\u0131zlar\u0131n ya\u015flanmas\u0131 ve \u00f6lmesi sonucu olu\u015fmu\u015ftur.<\/p>\n
Evrende bug\u00fcn var olan anakol evresindeki y\u0131ld\u0131zlar\u0131n say\u0131ca y\u00fczde 0.7\u2019si A, y\u00fczde 2\u2019si F tayf t\u00fcr\u00fc y\u0131ld\u0131zlard\u0131r.<\/p>\n
G\u00fcne\u015f\u2019in 3.5 ila 120 kat\u0131 k\u00fctleye sahip olan O ve B tipi dev y\u0131ld\u0131zlar i\u00e7in anakol evresi, k\u00fctle miktar\u0131ndaki de\u011fi\u015fime g\u00f6re 1 ila 150 milyon y\u0131l aras\u0131d\u0131r. Bu s\u00fcre sonunda y\u0131ld\u0131z h\u0131zla bir k\u0131rm\u0131z\u0131 deve, ard\u0131ndan \u2013en b\u00fcy\u00fck k\u00fctleli olanlar\u0131\u2013 s\u00fcpernova patlamas\u0131yla n\u00f6tron y\u0131ld\u0131z\u0131 veya kara deli\u011fe d\u00f6n\u00fc\u015f\u00fcr. Daha d\u00fc\u015f\u00fck k\u00fctleli olanlar ise, k\u0131rm\u0131z\u0131 dev evresinden sonra bir gezegenimsi bulutsu meydana getirerek beyaz c\u00fcce olarak hayata veda ederler.<\/p>\n
Bu y\u0131ld\u0131zlar, evrende say\u0131ca en az bulunan y\u0131ld\u0131z t\u00fcr\u00fcd\u00fcr ve t\u00fcm y\u0131ld\u0131zlar\u0131n sadece y\u00fczde 0.1\u2019i B, y\u00fczde 0.00001\u2019i O tayft t\u00fcr\u00fc y\u0131ld\u0131zlard\u0131r.<\/p>\n
Anakol evresinin sonuna gelip ya\u015flanan y\u0131ld\u0131z\u0131n \u00e7ekirde\u011findeki hidrojen t\u00fckendi\u011finde, art\u0131k y\u0131ld\u0131z\u0131 do\u011fdu\u011fu g\u00fcnden beri i\u00e7e \u00e7\u00f6kmeye zorlayan k\u00fctle \u00e7ekimine kar\u015f\u0131 koyan \u0131\u015f\u0131n\u0131m bas\u0131nc\u0131 azal\u0131r ve y\u0131ld\u0131z\u0131n hidrostatik dengesi bozulur.<\/p>\n
Bozulan bu denge nedeniyle k\u00fctle \u00e7ekim g\u00fcc\u00fc bask\u0131n hale gelir ve y\u0131ld\u0131z\u0131 olu\u015fturan madde kendi a\u011f\u0131rl\u0131\u011f\u0131 alt\u0131nda i\u00e7e \u00e7\u00f6k\u00fcp s\u0131k\u0131\u015fmaya ba\u015flar.Y\u0131ld\u0131z \u00e7\u00f6kt\u00fck\u00e7e, s\u0131k\u0131\u015fan \u00e7ekirdek b\u00f6lgesindeki bas\u0131n\u00e7 ve \u0131s\u0131 artar. Bas\u0131n\u00e7 ve s\u0131k\u0131\u015fman\u0131n yaratt\u0131\u011f\u0131 \u0131s\u0131 \u00e7ekirdekte 100 milyon santigrat dereceyi buldu\u011funda, \u00e7ekirdekte birikmi\u015f olan Helyum atomlar\u0131, birle\u015ferek karbon atomlar\u0131 meydana getirmeye ba\u015flar.<\/p>\n
Ayn\u0131 anda, \u00e7ekirdek \u00e7evresinde kalm\u0131\u015f ama reaksiyonu durmu\u015f olan t\u00fcm hidrojen de tepkimeye girer. Ortaya \u00e7\u0131kan bu ani ve muazzam enerji y\u0131ld\u0131z\u0131n \u00e7\u00f6kmesini engelledi\u011fi gibi, daha ba\u015fka bir \u015feye de sebep olur: Y\u0131ld\u0131z geni\u015flemeye ba\u015flar. Bu geni\u015fleyen y\u0131ld\u0131zlara \u201ck\u0131rm\u0131z\u0131 dev\u201d diyoruz.<\/p>\n
Tipik bir k\u0131rm\u0131z\u0131 dev y\u0131ld\u0131z, ba\u015flang\u0131\u00e7 k\u00fctlesine g\u00f6re anakol evresindeki \u00e7ap\u0131n\u0131n 100 ila birka\u00e7 bin kat\u0131 boyuta ula\u015fabilir.<\/p>\n","protected":false},"excerpt":{"rendered":"
Anakol y\u0131ld\u0131zlar\u0131 k\u00fctlelerine g\u00f6re (G\u00fcne\u015f\u2019in k\u00fctlesini \u201c1\u201d olarak al\u0131yoruz) s\u0131n\u0131fland\u0131r\u0131ld\u0131klar\u0131nda, en a\u011f\u0131rdan en hafife do\u011fru; O, B, A, F, G, K ve M harfleriyle sembolize edilirler. Bu harfler, anakol y\u0131ld\u0131z\u0131n\u0131n k\u00fctlesini ve ayn\u0131 zamanda tayf t\u00fcr\u00fcn\u00fc sembolize eder. Y\u0131ld\u0131z\u0131n do\u011fum an\u0131ndaki k\u00fctlesine g\u00f6re, anakol evresinin s\u00fcresi de\u011fi\u015fiklik g\u00f6sterse de, \u00f6n\u00fcnde sonunda gen\u00e7lik g\u00fcnleri sona eren […]<\/p>\n","protected":false},"author":23,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[506],"tags":[],"class_list":["post-85503","post","type-post","status-publish","format-standard","hentry","category-astronomi"],"acf":[],"yoast_head":"\n