Uzaklardaki bir y\u0131ld\u0131z, g\u00fcney g\u00f6ky\u00fcz\u00fcnde garip bir \u015fekilde titre\u015fiyor; bu durumsa garip bir materyal bulutunun (ve belki de uzayl\u0131 \u00fcretimi bir \u015feyin) \u00e7evresinde y\u00f6r\u00fcngede oldu\u011funu g\u00f6steriyor. \u015eili\u2019de bulunan bir teleskobu kullanan g\u00f6kbilimciler taraf\u0131ndan ke\u015ffedilen y\u0131ld\u0131z iki astrofiziksel nesneye daha sahip gibi g\u00f6r\u00fcn\u00fcyor; bunlardan birinin, Sat\u00fcrn\u2019\u00fcnkilerden 200 kat daha b\u00fcy\u00fck halkalara sahip olan bir gezegen, di\u011ferinin ise uzayl\u0131 devasa yap\u0131lar taraf\u0131ndan \u00e7evrelenmi\u015f bir g\u00f6k cismi oldu\u011fu d\u00fc\u015f\u00fcn\u00fcl\u00fcyor. \u201cYeni ke\u015ffedilen y\u0131ld\u0131z, bu kafa kar\u0131\u015ft\u0131r\u0131c\u0131 nesnelerin birinde ya da her ikisinin \u00fczerine bir miktar \u0131\u015f\u0131\u011f\u0131n tutulmas\u0131na olanak sa\u011fl\u0131yor olabilir.\u201d 2010 y\u0131l\u0131nda, \u2018Via Lactea\u2019 (VVV) ara\u015ft\u0131rmas\u0131nda yer alan Vista De\u011fi\u015fkenleri, Samanyolu merkezinin yak\u0131n\u0131nda bulunan de\u011fi\u015fken y\u0131ld\u0131zlar\u0131n \u00fc\u00e7 boyutlu bir haritas\u0131n\u0131 olu\u015fturma projesine ba\u015flad\u0131. Projenin bir par\u00e7as\u0131 olan Santa Catarina Federal \u00dcniversitesi\u2019nden g\u00f6kbilimci Roberto Saito, takip alt\u0131ndaki y\u00fcz milyonlarca y\u0131ld\u0131zda ortaya \u00e7\u0131kan patlamalara ili\u015fkin teleskobun sa\u011flad\u0131\u011f\u0131 verileri inceledi. Ne var ki buldu\u011fu en dikkat \u00e7ekici \u015fey bir patlama de\u011fildi. 2012 y\u0131l\u0131nda, birka\u00e7 g\u00fcn i\u00e7inde gizemli bir \u015fekilde b\u00fcy\u00fcyen bir y\u0131ld\u0131zd\u0131. Saito ve arkada\u015flar\u0131, Kraliyet Astronomi Derne\u011fi\u2019nin Ayl\u0131k Notlar adl\u0131 sayfas\u0131nda yay\u0131nlanan bir makalede tespitlerini payla\u015ft\u0131lar.<\/p>\n
VVV-WIT-07 ad\u0131yla bilinen y\u0131ld\u0131z, g\u00fcne\u015f sistemimizden \u00e7ok daha ya\u015fl\u0131 ve daha k\u0131rm\u0131z\u0131 g\u00f6r\u00fcn\u00fcyor; \u00f6te yandan, g\u00fcne\u015f sistemimizle y\u0131ld\u0131z\u0131n galaktik merkeze olan mesafesi aras\u0131nda bulunan y\u0131ld\u0131zlar aras\u0131 toz miktar\u0131, kesin bir s\u0131n\u0131fland\u0131rma yapmay\u0131 ve mesafe \u00f6l\u00e7\u00fcm\u00fcn\u00fc olduk\u00e7a zor bir hale getiriyor. Kesin olan \u015fey, 2012 yaz\u0131nda, cismin parlakl\u0131\u011f\u0131n\u0131n 11 g\u00fcn boyunca hafif bi\u00e7imde solmas\u0131 ve daha sonraki 48 g\u00fcn boyunca d\u00fc\u015fmesi; bunlar, y\u0131ld\u0131z\u0131n \u0131\u015f\u0131\u011f\u0131n\u0131n D\u00fcnya\u2019ya do\u011fru ak\u0131\u015f\u0131n\u0131n d\u00f6rtte \u00fc\u00e7\u00fcnden fazlas\u0131n\u0131n bir \u015fey taraf\u0131ndan engellendi\u011fini d\u00fc\u015f\u00fcnd\u00fcr\u00fcyor. Peki, bu \u201c\u015fey\u201d ne olabilir? NASA\u2019n\u0131n VVV ara\u015ft\u0131rmas\u0131yla bir ilgisi olmayan Jet \u0130ti\u015f Laboratuvar\u0131\u2019nda astrofizik\u00e7i olan Eric Mamajek\u2019e g\u00f6re, bu denli koyu bir kararma seviyesi, \u015fa\u015f\u0131rt\u0131c\u0131 \u00f6l\u00e7\u00fcde b\u00fcy\u00fck bir nesne veya nesne grubunun \u0131\u015f\u0131\u011f\u0131 engelledi\u011fini g\u00f6steriyor. \u201cBir milyon kilometreden daha geni\u015f ve y\u0131ld\u0131z \u0131\u015f\u0131\u011f\u0131n\u0131 a\u015f\u0131r\u0131 d\u00fczeyde engelleyebilecek kadar yo\u011fun olmal\u0131\u201d diyor. Mamajek\u2019in bir noktay\u0131 anlamas\u0131 gerekiyor: Kendisi, J1407\u2019yi ke\u015ffeden ekibi y\u00f6netirken, bir ba\u015fka tuhaf y\u0131ld\u0131z daha periyodik bi\u00e7imde gezegen b\u00fcy\u00fckl\u00fc\u011f\u00fcnde bir nesne ile tutulma ya\u015f\u0131yor ve ekibi, cismin Sat\u00fcrn\u2019\u00fcnkinden 200 kat daha geni\u015f k\u00fctledeki bir halka sistemine sahip oldu\u011funu d\u00fc\u015f\u00fcn\u00fcyor. Bu son durumda, VVV-WIT-07\u2019den gelen garip sinyallerin, gezegenle y\u0131ld\u0131z aras\u0131ndan ge\u00e7i\u015f yapan materyal y\u0131\u011f\u0131nlar\u0131ndan ya da bulutlardan kaynaklanabilece\u011fini s\u00f6yl\u00fcyor; yan\u0131 s\u0131ra, eldeki verilerin \u00f6nc\u00fcl bulgular oldu\u011funun ve daha fazla g\u00f6zlem yap\u0131lmas\u0131 gerekti\u011finin alt\u0131n\u0131 \u00e7iziyor.<\/p>\n
Tabetha Boyajian da onunla ayn\u0131 fikirde. Louisiana Eyalet \u00dcniversitesi\u2019nde bir g\u00f6kbilimci olan Boyajian, ilk kez NASA\u2019ya ait Kepler Uzay Teleskobu taraf\u0131ndan fark edilen s\u0131ra d\u0131\u015f\u0131 bir nesne olan ve \u2018Tabby Y\u0131ld\u0131z\u0131\u2019 diye de bilinen KIC 8462852\u2019nin ya\u015fad\u0131\u011f\u0131 garip karartmay\u0131 anlatan 2015 tarihli makalenin ba\u015fyazar\u0131yd\u0131. Boyajian, VVV-WIT-07\u2019nin \u201cbu \u00e7e\u015fit batma-\u00e7\u0131kmalar yapmas\u0131 i\u00e7in olduk\u00e7a tuhaf bir toz bulutu\u201d bar\u0131nd\u0131rmas\u0131 gerekti\u011fini s\u00f6yl\u00fcyor. Boyajian\u2019\u0131n \u00e7al\u0131\u015fmas\u0131, kamuoyunun ilgisini Tabby Y\u0131ld\u0131z\u0131\u2019na \u00e7ekmeye yard\u0131m etmi\u015fti; zira, y\u0131ld\u0131z\u0131n ya\u015fad\u0131\u011f\u0131 s\u0131ra d\u0131\u015f\u0131 kararma, y\u0131ld\u0131z\u0131n \u0131\u015f\u0131\u011f\u0131n\u0131 toplayan yapay bir yap\u0131 (Dyson K\u00fcresi) in\u015fa edebilen yabanc\u0131 bir uygarl\u0131\u011f\u0131n kan\u0131t\u0131 olarak da g\u00f6r\u00fclebilir. Daha geleneksel a\u00e7\u0131klamalar, par\u00e7alanm\u0131\u015f bir gezegenden geriye kalan kuyruklu y\u0131ld\u0131zlara ya da materyal y\u0131\u011f\u0131nlar\u0131na vurgu yap\u0131yor; bu kal\u0131nt\u0131lar\u0131n ikisi de y\u0131ld\u0131z\u0131n \u0131\u015f\u0131\u011f\u0131n\u0131 engelleyebilecek miktarda toz ve enkaz bulutlar\u0131 yaratabilir. Ne var ki, \u015fimdiye dek, y\u0131ld\u0131z\u0131n etraf\u0131nda g\u00f6zlemlenen kararman\u0131n karma\u015f\u0131kl\u0131\u011f\u0131na ili\u015fkin basit bir a\u00e7\u0131klama yap\u0131lamad\u0131; Ara\u015ft\u0131rmac\u0131lar, Tabby Y\u0131ld\u0131z\u0131\u2019n\u0131n ya\u015fad\u0131\u011f\u0131 garip kararman\u0131n as\u0131l do\u011fas\u0131n\u0131 anlama \u00e7abalar\u0131n\u0131 s\u00fcrd\u00fcr\u00fcyorlar.<\/p>\n
G\u00f6kbilimciler, bir y\u0131ld\u0131z\u0131n \u0131\u015f\u0131\u011f\u0131n\u0131n yo\u011funlu\u011fundaki de\u011fi\u015fimleri \u201c\u0131\u015f\u0131k e\u011frisi\u201d olarak bilinen bir \u015fekil do\u011frultusunda ve zaman bazl\u0131 olarak \u00e7izerek, bu t\u00fcr dalgalanmalar\u0131 takip ederler. J1407\u2019nin \u0131\u015f\u0131k e\u011frisi, (gezegen etraf\u0131ndaki) b\u00fcy\u00fck halkalar\u0131n kimi zaman y\u0131ld\u0131z\u0131n \u0131\u015f\u0131\u011f\u0131n\u0131n yakla\u015f\u0131k y\u00fczde 95\u2019ini engelleyebilece\u011fini g\u00f6steriyor. Tabby Y\u0131ld\u0131z\u0131\u2019n\u0131n \u0131\u015f\u0131k e\u011frisi, y\u00f6r\u00fcngesinde bulunan cisimlerin y\u0131ld\u0131z\u0131n \u0131\u015f\u0131k yay\u0131l\u0131m\u0131n\u0131n yaln\u0131zca y\u00fczde 20\u2019sini engelledi\u011fini d\u00fc\u015f\u00fcnd\u00fcr\u00fcyor. Saito\u2019ya g\u00f6re bu durum, VVV-WIT-07\u2019yi orta d\u00fczeyde bir olgu haline getiriyor. \u201cCismimiz, y\u0131ld\u0131z\u0131n \u00e7evresindeki maddelere dayanarak \u0131\u015f\u0131k e\u011frisindeki davran\u0131\u015flar\u0131 a\u00e7\u0131klamaya \u00e7al\u0131\u015ft\u0131\u011f\u0131m\u0131z noktada, di\u011feriyle benze\u015fiyor\u201d diyor.<\/p>\n
Saito ve meslekta\u015flar\u0131, 2016 y\u0131l\u0131nda yap\u0131lan takip g\u00f6zlemleri de dahil olmak \u00fczere, bulgulara dayanarak, y\u0131ld\u0131z\u0131n 2019\u2019da da titre\u015fmeyi s\u00fcrd\u00fcrebilece\u011fini \u00f6ng\u00f6r\u00fcyor ve gizemli \u0131\u015f\u0131k engelleyici materyal y\u0131ld\u0131z\u0131n y\u00f6r\u00fcngesinde d\u00f6nmeye devam ederken, potansiyel olarak y\u0131l boyunca d\u00f6rt kararma olay\u0131 daha ya\u015fanabilece\u011fini tahmin ediyorlar. \u015eayet bu tahminler do\u011fru \u00e7\u0131karsa, yaln\u0131zca VVV-WIT-07\u2019nin ard\u0131nda yatan gizemlerin de\u011fil, ayn\u0131 zamanda Tabby Y\u0131ld\u0131z\u0131\u2019n\u0131 \u00e7evreleyen bilinmezlerin kilidini a\u00e7mak i\u00e7in bir anahtar niteli\u011finde olabilirler.
\nBoyajian, \u201c\u0130ki \u00f6rne\u011fe sahip oldu\u011fumuzda, neler olup bitti\u011fine dair bir teoriyi birle\u015ftirmeye \u00e7al\u0131\u015fmak yerine iki y\u0131ld\u0131z \u00fczerinde \u00e7al\u0131\u015fabiliriz\u201d diyor. Her iki y\u0131ld\u0131z\u0131n kararmas\u0131 da ayn\u0131 do\u011fal s\u00fcre\u00e7lerden kaynaklan\u0131yorsa, bu durum devasa boyutlardaki kozmik in\u015faat projeleri gibi s\u0131ra d\u0131\u015f\u0131 olaylar\u0131n ger\u00e7ekle\u015fmesi ihtimalini daha az olas\u0131 k\u0131lar.<\/p>\n
Yak\u0131n gelecekte, bu t\u00fcrden garip bi\u00e7imde titre\u015fen y\u0131ld\u0131zlar\u0131n bir\u00e7ok benzerinin ortaya \u00e7\u0131kmas\u0131n\u0131 umut ediyoruz. Saito, VVV ara\u015ft\u0131rmas\u0131n\u0131n, bu t\u00fcr sistemleri tan\u0131mlamak amac\u0131yla tasarlanm\u0131\u015f olmasa bile, daha fazla ke\u015ffin \u00f6n\u00fcn\u00fc a\u00e7aca\u011f\u0131n\u0131 s\u00f6yl\u00fcyor. \u015eili\u2019de hen\u00fcz yap\u0131m a\u015famas\u0131nda ve 8.4 metrelik bir g\u00f6zlem arac\u0131 olan \u201cB\u00fcy\u00fck Sinoptik Ara\u015ft\u0131rma Teleskobu\u201d (LSST), 2020\u2019lerde faaliyete ba\u015flad\u0131\u011f\u0131 zaman daha fazla say\u0131da tuhaf cismin olu\u015fturaca\u011f\u0131 bir koleksiyon yaratabiliriz.
\nMamajek, \u201cSan\u0131r\u0131m, LSST faaliyete ge\u00e7ti\u011finde buna benzer \u00e7ok daha fazla cisim bulmaya ba\u015flayaca\u011f\u0131z\u201d diyor: \u201cB\u00fcy\u00fck olas\u0131l\u0131kla daha \u00f6nce g\u00f6r\u00fclmemi\u015f olan garip de\u011fi\u015fkenleri ke\u015ffetmeye ba\u015flayaca\u011f\u0131z.\u201d
\nSaito ve meslekta\u015flar\u0131, \u015fimdilik her ikisi de ekibin 2016 g\u00f6zlemlerine katk\u0131da bulunan ESO\u2019nun (Avrupa Uzay Ajans\u0131) Yeni Teknoloji Teleskobu ve Ulusal Optik Astronomi G\u00f6zlemevi\u2019nin G\u00fcney Astrofiziksel Ara\u015ft\u0131rma Teleskobu\u2019ndaki k\u0131z\u0131l\u00f6tesi ara\u00e7larla VVV-WIT-07\u2019yi g\u00f6zlemlemeye devam etmeyi planl\u0131yorlar. (I\u015f\u0131\u011f\u0131n\u0131n engin galaksi bo\u015fluklar\u0131 boyunca zay\u0131flamas\u0131n\u0131n yan\u0131 s\u0131ra) Y\u0131ld\u0131z\u0131n yap\u0131sal zay\u0131fl\u0131\u011f\u0131, y\u0131ld\u0131zlar aras\u0131 tozdan kaynaklanan etkile\u015fimin minimal oldu\u011fu yak\u0131n k\u0131z\u0131l\u00f6tesi dalga boylar\u0131nda iyi bi\u00e7imde g\u00f6zlemlenebilmesine olanak sa\u011fl\u0131yor. VVV ara\u015ft\u0131rmas\u0131 ge\u00e7ti\u011fimiz y\u0131l sonu\u00e7lanm\u0131\u015f olsa da h\u00e2lihaz\u0131rda daha geni\u015fletilmi\u015f bir ara\u015ft\u0131rma galaksi merkezini g\u00f6zlemlemeyi s\u00fcrd\u00fcr\u00fcyor ve ilk g\u00f6zlemlerde g\u00f6zden ka\u00e7\u0131r\u0131lan di\u011fer tutulmalar\u0131n da tespit edilmesi bekleniyor.
\nUmudumuz, bu g\u00f6zlemlerin VVV-WIT-07\u2019nin ya\u015fad\u0131\u011f\u0131 garip kararmalara yol a\u00e7an olguya biraz \u0131\u015f\u0131k tutmas\u0131. Mamajek, \u201cBu, kesinlikle ortak bir olgu de\u011fil\u201d diyor: \u201cGelecekte elde edilecek sonu\u00e7lar\u0131 g\u00f6rmek i\u00e7in sab\u0131rs\u0131zlan\u0131yorum.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
Uzaklardaki bir y\u0131ld\u0131z, g\u00fcney g\u00f6ky\u00fcz\u00fcnde garip bir \u015fekilde titre\u015fiyor; bu durumsa garip bir materyal bulutunun (ve belki de uzayl\u0131 \u00fcretimi bir \u015feyin) \u00e7evresinde y\u00f6r\u00fcngede oldu\u011funu g\u00f6steriyor. \u015eili\u2019de bulunan bir teleskobu kullanan g\u00f6kbilimciler taraf\u0131ndan ke\u015ffedilen y\u0131ld\u0131z iki astrofiziksel nesneye daha sahip gibi g\u00f6r\u00fcn\u00fcyor; bunlardan birinin, Sat\u00fcrn\u2019\u00fcnkilerden 200 kat daha b\u00fcy\u00fck halkalara sahip olan bir gezegen, di\u011ferinin […]<\/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-49008","post","type-post","status-publish","format-standard","hentry","category-astronomi"],"acf":[],"yoast_head":"\n