G\u00f6kbilimciler, Samanyolu Galaksisi\u2019nde demir a\u00e7\u0131s\u0131ndan en yoksul olan y\u0131ld\u0131z\u0131 tespit ettiler. Ke\u015ffedilen y\u0131ld\u0131z, evrenin olu\u015ftu\u011fu d\u00f6nemde ortaya \u00e7\u0131kan ilk y\u0131ld\u0131zlar\u0131ndan kalan maddelerle olu\u015fmu\u015f gibi g\u00f6r\u00fcn\u00fcyor.<\/p>\n
Ara\u015ft\u0131rmac\u0131lar, yeni ke\u015ffedilen ve rekor d\u00fczeyde d\u00fc\u015f\u00fck demir seviyesine sahip ya\u015fl\u0131 bir y\u0131ld\u0131z\u0131n, uzun zamand\u0131r varsay\u0131lan ama ortadan kayboldu\u011fu d\u00fc\u015f\u00fcn\u00fclen daha ya\u015fl\u0131 y\u0131ld\u0131zlara ait bir t\u00fcr\u00fcn kan\u0131tlar\u0131n\u0131 bar\u0131nd\u0131rd\u0131\u011f\u0131n\u0131 ifade ediyorlar.<\/p>\n
Avustralya\u2019dan Thomas Nordlander\u2019\u0131n liderli\u011findeki bir ara\u015ft\u0131rma grubunun Royal Astronomical Society\u2019in ayl\u0131k yay\u0131nlar dergisinde yay\u0131nlad\u0131\u011f\u0131 makale, Samanyolu\u2019nun halesinde, D\u00fcnya\u2019dan yakla\u015f\u0131k 35 bin \u0131\u015f\u0131ky\u0131l\u0131 mesafede bulunan ve a\u011f\u0131r metaller a\u00e7\u0131s\u0131ndan a\u015f\u0131r\u0131 derecede yoksul olan bir \u2018k\u0131rm\u0131z\u0131 dev\u2019 y\u0131ld\u0131zdan bahsediyor.<\/p>\n
ARC\u2019nin 3 boyutlu T\u00fcm G\u00f6ky\u00fcz\u00fc Astrofizi\u011fi Uzmanl\u0131k Merkezi\u2019nde (ASTRO 3D) \u00e7al\u0131\u015fmalar\u0131n\u0131 y\u00fcr\u00fcten Nordlander, Avustralya, ABD, Almanya, \u0130sve\u00e7 ve \u0130talya\u2019dan meslekta\u015flar\u0131yla birlikte \u00e7al\u0131\u015f\u0131yor.<\/p>\n
Ke\u015ffettikleri yeni y\u0131ld\u0131z\u0131, Avustralya Ulusal \u00dcniversitesi\u2019ne ait SkyMapper (G\u00f6ky\u00fcz\u00fc Haritalama) Teleskobu\u2019nu kullanarak buldular. Yap\u0131lan inceleme, y\u0131ld\u0131z\u0131n 50 milyarda 1 gibi gayet d\u00fc\u015f\u00fck bir demir i\u00e7eri\u011fine sahip oldu\u011funu ortaya koydu.<\/p>\n
Nordlander, \u201cBu oran, olimpik y\u00fczme havuzundaki bir damla suya benziyor\u201d diyor. \u201cB\u00fcy\u00fck Patlama\u2019dan yaln\u0131zca birka\u00e7 y\u00fcz milyon y\u0131l sonra olu\u015fmu\u015f bu inan\u0131lmaz derecede anemik y\u0131ld\u0131z, G\u00fcne\u015f\u2019in sahip oldu\u011fundan 1,5 milyon kat daha d\u00fc\u015f\u00fck demir seviyelerine sahip.\u201d<\/p>\n
Bu \u00f6zelli\u011fi, \u2018SMSS J160540.18\u2013144323.1\u2019 bi\u00e7iminde adland\u0131r\u0131lan y\u0131ld\u0131z\u0131n rekor kitaplar\u0131na al\u0131nmas\u0131 i\u00e7in yeterli bir oran ama ayn\u0131 zamanda en ilgi \u00e7ekici olan taraf\u0131, d\u00fc\u015f\u00fck demir seviyesinin ortaya \u00e7\u0131k\u0131\u015f nedeni.<\/p>\n
Evrende olu\u015fan ilk y\u0131ld\u0131zlar\u0131n, yaln\u0131zca hidrojen ve helyumdan olu\u015ftu\u011fu, lityum izleri de ta\u015f\u0131d\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fcl\u00fcyor. Bu elementler B\u00fcy\u00fck Patlama\u2019n\u0131n hemen sonras\u0131nda ortaya \u00e7\u0131karken, di\u011fer t\u00fcm a\u011f\u0131r elementler s\u00fcpernovalar\u0131n deh\u015fet verici \u0131s\u0131s\u0131ndan ve bas\u0131nc\u0131ndan dolay\u0131 ortaya \u00e7\u0131km\u0131\u015ft\u0131r.<\/p>\n
Bu sebeple, a\u011f\u0131r elementler bak\u0131m\u0131ndan zengin olan G\u00fcne\u015f gibi y\u0131ld\u0131zlar, s\u00fcpernova haline gelerek patlayan bir\u00e7ok y\u0131ld\u0131z g\u00f6vdesinden kalan malzemeleri bar\u0131nd\u0131r\u0131r.<\/p>\n
\u015eimdiye de ilk y\u0131ld\u0131zlara ait hi\u00e7bir \u00f6rnek bulunamad\u0131\u011f\u0131ndan ve hi\u00e7bir zaman da bulunamayaca\u011f\u0131ndan dolay\u0131, \u00f6zellikleri varsay\u0131msal kalmaya devam ediyor. Olu\u015fturulan hipotez, G\u00fcne\u015f\u2019ten belki de y\u00fczlerce kat daha b\u00fcy\u00fck olan ve \u2018hipernova\u2019 denilen inan\u0131lmaz enerjiye sahip s\u00fcpernova patlamalar\u0131yla ilgili bir varsay\u0131ma dayan\u0131yor.<\/p>\n
Anemik y\u0131ld\u0131z SMSS J160540.18\u2013144323.1\u2019in varl\u0131\u011f\u0131n\u0131n do\u011frulanmas\u0131, bizzat ilk y\u0131ld\u0131zlardan biri olmasa bile elimizdeki bilgilere yeni ayr\u0131nt\u0131lar ekleyecek.<\/p>\n
Nordlander ve \u00e7al\u0131\u015fma arkada\u015flar\u0131, bu y\u0131ld\u0131z\u0131n, evrendeki ilk y\u0131ld\u0131zlardan birinin patlamas\u0131n\u0131n ard\u0131ndan olu\u015ftu\u011funu ileri s\u00fcr\u00fcyorlar. Patlayan y\u0131ld\u0131z, G\u00fcne\u015f\u2019ten yaln\u0131zca 10 kat daha b\u00fcy\u00fck yap\u0131s\u0131yla etkileyiciydi; s\u00fcpernova, yaratt\u0131\u011f\u0131 a\u011f\u0131r elementlerin \u00e7o\u011funun ard\u0131nda b\u0131rakt\u0131\u011f\u0131 n\u00f6tron y\u0131ld\u0131z\u0131na geri d\u00f6nebilece\u011fi bi\u00e7imde (astronomik \u00f6l\u00e7ekte), gayet zay\u0131f bir \u015fekilde patlam\u0131\u015ft\u0131.<\/p>\n
Yaln\u0131zca az miktardaki yeni d\u00f6v\u00fclm\u00fc\u015f demir kal\u0131nt\u0131lar\u0131n yer\u00e7ekimsel etkisinden kurtulabildi ve \u00e7ok daha b\u00fcy\u00fck miktarlardaki hafif elementlerle birlikte yeni bir y\u0131ld\u0131z olu\u015fturmak \u00fczere yoluna devam etti; netice olarak, yeni ke\u015ffetti\u011fimiz ikinci nesil y\u0131ld\u0131zlar\u0131ndan biri haline geldi.<\/p>\n
*Anemik, yayg\u0131n bilinen ad\u0131yla \u2018kans\u0131zl\u0131k\u2019, toplam k\u0131rm\u0131z\u0131 kan h\u00fccresi\/alyuvar\/eritrosit say\u0131s\u0131n\u0131n azalmas\u0131 veya eritrositlerin i\u00e7indeki hemoglobin miktar\u0131n\u0131n azalmas\u0131 ya da her ikisinin birlikte olmas\u0131 sonucu olu\u015fan bir hastal\u0131kt\u0131r. Terim, bu yaz\u0131da y\u0131ld\u0131z\u0131n \u2018demir a\u00e7\u0131s\u0131ndan fakir i\u00e7eri\u011fine\u2019 vurgu yap\u0131yor.<\/p>\n","protected":false},"excerpt":{"rendered":"
G\u00f6kbilimciler, Samanyolu Galaksisi\u2019nde demir a\u00e7\u0131s\u0131ndan en yoksul olan y\u0131ld\u0131z\u0131 tespit ettiler. Ke\u015ffedilen y\u0131ld\u0131z, evrenin olu\u015ftu\u011fu d\u00f6nemde ortaya \u00e7\u0131kan ilk y\u0131ld\u0131zlar\u0131ndan kalan maddelerle olu\u015fmu\u015f gibi g\u00f6r\u00fcn\u00fcyor. Ara\u015ft\u0131rmac\u0131lar, yeni ke\u015ffedilen ve rekor d\u00fczeyde d\u00fc\u015f\u00fck demir seviyesine sahip ya\u015fl\u0131 bir y\u0131ld\u0131z\u0131n, uzun zamand\u0131r varsay\u0131lan ama ortadan kayboldu\u011fu d\u00fc\u015f\u00fcn\u00fclen daha ya\u015fl\u0131 y\u0131ld\u0131zlara ait bir t\u00fcr\u00fcn kan\u0131tlar\u0131n\u0131 bar\u0131nd\u0131rd\u0131\u011f\u0131n\u0131 ifade ediyorlar. […]<\/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-105965","post","type-post","status-publish","format-standard","hentry","category-astronomi"],"acf":[],"yoast_head":"\n