\nS\u00fcpernovalar G\u00fcne\u015f\u2019ten en az sekiz kat daha k\u00fctleli y\u0131ld\u0131zlar\u0131n \u015fiddetli \u00f6l\u00fcmlerinin i\u015faret\u00e7isidir. Ancak astronomlar da\u011f\u0131lmak \u00fczere olan bir y\u0131ld\u0131z\u0131n nas\u0131l bir sinyal verdi\u011fi bilgisine hala sahip de\u011filler. Patlayan y\u0131ld\u0131zlar gezegenleri ve insanlar\u0131 (ve daha pek \u00e7ok \u015feyi) meydana getiren elementlerin (\u00f6rne\u011fin karbon, oksijen ve demir) \u00e7o\u011funlu\u011funu y\u0131ld\u0131zlararas\u0131 uzaya serpi\u015ftirir. Yani s\u00fcpernovalar\u0131n nas\u0131l meydana geldi\u011fi sorusu, kendi k\u00f6kenimize dair de bir sorudur.<\/p>\n
Ancak patlamalar nadir ger\u00e7ekle\u015fir; astronomlar\u0131n tahminine g\u00f6re y\u00fczy\u0131lda sadece birka\u00e7 kez. Yak\u0131nlar\u0131m\u0131zda (kom\u015fumuz olan bir galakside) g\u00f6r\u00fclen son s\u00fcpernova olan SN 1987A\u2019n\u0131n ke\u015ffi g\u00fcn\u00fcm\u00fczden 33 y\u0131l \u00f6nceye uzan\u0131yor. Betelgeuse, her an s\u00fcpernova patlamas\u0131 ge\u00e7irebilecek, ya\u015f\u0131 ileri ve b\u00fcy\u00fck k\u00fctleli \u2013\u201ck\u0131rm\u0131z\u0131 s\u00fcper dev\u201d evresindeki\u2013 pek \u00e7ok y\u0131ld\u0131zdan sadece biri. Ancak bunlar\u0131n i\u00e7erisinde bize en yak\u0131n ve parlak olanlar\u0131ndan oldu\u011fundan, uzay merakl\u0131lar\u0131 taraf\u0131ndan en iyi bilineni.<\/p>\n
Y\u0131ld\u0131z, 2019\u2019un sonuna do\u011fru garip davran\u0131\u015flar g\u00f6stermeye ba\u015flay\u0131nca, Montarg\u00e8s ve Betelgeuse’\u00fcn sevenlerinden olu\u015fan k\u00fc\u00e7\u00fck bir grup, ula\u015fabildikleri t\u00fcm teleskoplar\u0131 s\u00f6n\u00fckle\u015fmekte olan bu deve \u00e7evirdiler. Takip eden aylarda y\u0131ld\u0131z al\u0131\u015f\u0131ld\u0131k parlakl\u0131\u011f\u0131na geri d\u00f6nd\u00fc ve eli kula\u011f\u0131nda s\u00fcpernovaya kar\u015f\u0131 ilgi de b\u00f6ylece s\u00f6nmeye y\u00fcz tuttu. Yine de neler oldu\u011funu anlamak i\u00e7in aceleyle toplanan veri y\u0131\u011f\u0131n\u0131, uzun zamand\u0131r varl\u0131\u011f\u0131n\u0131 s\u00fcrd\u00fcren sorunun cevab\u0131n\u0131 bulmaya yard\u0131m edebilir; b\u00fcy\u00fck k\u00fctleli, ya\u015fl\u0131 y\u0131ld\u0131zlar hen\u00fcz patlamadan \u00f6nce gezegenlerin yap\u0131ta\u015f\u0131 olan “y\u0131ld\u0131z tozu”nu uzaya nas\u0131l yayarlar?<\/p>\n
Orion\u2019un omzu<\/strong> Dahas\u0131 Betelgeuse tam anlam\u0131yla bir devdir. Ya\u015fam istatistiklerine dair tahminler de\u011fi\u015fiklik g\u00f6steriyor olsa da, e\u011fer G\u00fcne\u015f Sistemi’nin merkezine oturtulsayd\u0131, c\u00fcssesiyle G\u00fcne\u015f\u2019ten J\u00fcpiter\u2019e kadar olan alan\u0131 doldururdu. \u00c7ap\u0131 G\u00fcne\u015f\u2019in \u00e7ap\u0131n\u0131n 750 ila 1,000 kat\u0131na, k\u00fctlesi ise G\u00fcne\u015f\u2019inkinin 15 ila 20 kat\u0131na kar\u015f\u0131l\u0131k gelir. D\u00fcnya\u2019dan uzakl\u0131\u011f\u0131 ise sadece 550 \u0131\u015f\u0131k y\u0131l\u0131d\u0131r. Bu \u00f6zellikleri, onu genel olarak g\u00f6ky\u00fcz\u00fcndeki \u2013g\u00f6zlendi\u011fi zamana ba\u011fl\u0131 olarak\u2013 en parlak alt\u0131nc\u0131 veya yedinci y\u0131ld\u0131z konumda tutar.<\/p>\n Betelgeuse\u2019\u00fcn parlakl\u0131\u011f\u0131 normal ko\u015fullarda bile de\u011fi\u015fiklik g\u00f6sterir. D\u0131\u015f katmanlar\u0131 s\u0131cak gaz ve plazmayla dolu kaynayan bir kazan gibidir. S\u0131cak malzeme y\u00fczeye do\u011fru y\u00fckseldik\u00e7e y\u0131ld\u0131z\u0131n parlakl\u0131\u011f\u0131 artarken, \u00e7ekirde\u011fe do\u011fru indik\u00e7e parlakl\u0131\u011f\u0131 azal\u0131r. Bu konveksiyon d\u00f6ng\u00fcs\u00fc Betelgeuse \u00fczerinde yar\u0131 d\u00fczenli \u015fekilde \u00e7al\u0131\u015fan (yakla\u015f\u0131k 400 g\u00fcnl\u00fck bir periyotta sal\u0131n\u0131m g\u00f6steren) bir karartma anahtar\u0131 i\u015flevi g\u00f6r\u00fcr. Ayr\u0131ca nedeni hen\u00fcz bilinmese de, y\u0131ld\u0131z\u0131n parlakl\u0131\u011f\u0131 alt\u0131 y\u0131ll\u0131k periyotlarla da de\u011fi\u015fim g\u00f6sterir.<\/p>\n Betelgeuse ile ilgili kesin olarak bilinen \u015fey, zaman\u0131n\u0131n dolmak \u00fczere oldu\u011fudur. Neredeyse 10 milyon y\u0131l ya\u015f\u0131ndad\u0131r; G\u00fcne\u015fimizin 4.6 milyar y\u0131l ya\u015f\u0131nda oldu\u011fu d\u00fc\u015f\u00fcn\u00fcl\u00fcrse gen\u00e7 say\u0131l\u0131r. Ancak Betelgeuse \u00e7ok b\u00fcy\u00fck bir k\u00fctleye sahip olmas\u0131 dolay\u0131s\u0131yla yak\u0131t\u0131n\u0131 \u00e7ok h\u0131zl\u0131 bir \u015fekilde t\u00fcketti\u011finden, bir k\u0131rm\u0131z\u0131 s\u00fcper dev olarak ya\u015fam\u0131n\u0131n son a\u015famas\u0131na ula\u015fm\u0131\u015ft\u0131r. \u00c7ok uzak olmayan bir gelecekte, y\u0131ld\u0131z kendi a\u011f\u0131rl\u0131\u011f\u0131n\u0131 ta\u015f\u0131may\u0131 s\u00fcrd\u00fcremeyecek ve kendi i\u00e7ine \u00e7\u00f6kerek s\u00fcpernova patlamas\u0131 ge\u00e7irecektir. Bunun ne zaman olaca\u011f\u0131n\u0131 kestirmek zor, \u00e7\u00fcnk\u00fc astronomik zaman zarf\u0131nda yak\u0131n gelecek, 200.000 y\u0131ll\u0131k bir s\u00fcreye kar\u015f\u0131l\u0131k gelmektedir.<\/p>\n Ekim 2019\u2019da Betelgeuse\u2019\u00fcn parlakl\u0131\u011f\u0131 azalmaya ba\u015flad\u0131 ki bu, kendi ba\u015f\u0131na garipsenecek bir durum de\u011fildi. Betelgeuse\u2019\u00fcn parlakl\u0131k d\u00f6ng\u00fclerini 1980\u2019lerden beri izleyen astronom Edward Guinan (Pensilvanya\u2019daki Villanova \u00dcniversitesi’nde ara\u015ft\u0131rmac\u0131) parlakl\u0131ktaki de\u011fi\u015fimin normal 400 g\u00fcnl\u00fck d\u00f6ng\u00fclerde kar\u015f\u0131la\u015f\u0131lana uydu\u011funu belirtiyor. Ancak y\u0131ld\u0131z Noel\u2019e kadar astronomlar\u0131n 100 y\u0131ldan uzun s\u00fcredir \u00f6l\u00e7\u00fcmledi\u011fi en d\u00fc\u015f\u00fck parlakl\u0131k seviyesine ula\u015ft\u0131 ve \u015eubat 2020\u2019ye kadar bu d\u00fc\u015f\u00fc\u015f devam etti.<\/p>\n Guinan durumu fark edip alarm veren ilk ki\u015filerdendi. Meslekta\u015flar\u0131 ile birlikte ilk olarak 7 Aral\u0131k\u2019ta ve sonra tekrar 23 Aral\u0131k\u2019ta The Astronomer\u2019s Telegram<\/em> web sitesine y\u0131ld\u0131z\u0131n s\u00f6n\u00fckle\u015fti\u011fini belirten ve di\u011fer astronomlar\u0131n da duruma g\u00f6z atmalar\u0131n\u0131 \u00f6neren bir bildiri g\u00f6nderdiler.<\/p>\n S\u00f6n\u00fckle\u015fmenin bir s\u00fcpernovan\u0131n habercisi oldu\u011funu d\u00fc\u015f\u00fcnmek i\u00e7in asl\u0131nda hi\u00e7bir neden yoktu; Guinan da bu kan\u0131dayd\u0131. Ancak bu patlamalar \u00e7ok nadir ger\u00e7ekle\u015fti\u011finden, astronomlar yak\u0131nda ger\u00e7ekle\u015fecek olan bir s\u00fcpernovan\u0131n nas\u0131l bir sinyal verebilece\u011fi konusunda yeterince bilgi sahibi de\u011filler. Belki de o sinyallerden biri buydu. Dolay\u0131s\u0131yla t\u00fcm astronomlar ve amat\u00f6r uzay merakl\u0131lar\u0131 durumdan haberdar olmal\u0131yd\u0131. Tabii beklenebilece\u011fi gibi, haber \u00e7evrimi\u00e7i ortamda k\u0131v\u0131lc\u0131m etkisi yaratt\u0131.<\/p>\n Harvard&Smithsonian\u2019a ba\u011fl\u0131 Astrofizik Merkezi\u2019nden astrofizik\u00e7i Andrea Dupree, Twitter\u2019da durumun histerik bir hal ald\u0131\u011f\u0131n\u0131 s\u00f6yl\u00fcyor. An\u0131msad\u0131\u011f\u0131 bir tweette patlaman\u0131n o gece ger\u00e7ekle\u015fece\u011fi “#HIDE” etiketi ile payla\u015f\u0131lm\u0131\u015f. Dupree ise buna, \u201cNereye saklayaca\u011f\u0131m? Masam\u0131n alt\u0131na m\u0131?\u201d diye kar\u015f\u0131l\u0131k veriyor. Hemen g\u00f6zlem planlar\u0131n\u0131 revize etmeye koyulsalar da, astronomlar\u0131n \u00e7o\u011fu Betelgeuse\u2019\u00fcn sonunun geldi\u011fine ger\u00e7ekten inanmad\u0131. Ancak bir k\u0131sm\u0131 ger\u00e7ekten heyecana kap\u0131ld\u0131. Buna ra\u011fmen Guinan\u2019a g\u00f6re, adeta Betelgeuse\u2019\u00fc g\u00f6zlerken kimse g\u00f6z\u00fcn\u00fc k\u0131rpmaya niyetli de\u011fildi. Olas\u0131 bir s\u00fcpernova sonucu ortaya \u00e7\u0131kabilecek n\u00f6trinolar\u0131 ve k\u00fctle\u00e7ekimsel dalgalar\u0131 (uzay-zamandaki dalgalanmalar) \u00f6l\u00e7\u00fcmleyen enstr\u00fcmanlar\u0131n verece\u011fi sonu\u00e7lar \u00f6nemliydi. Bunlardan birinin tespit edilmesi s\u00fcpernovan\u0131n habercisi olabilirdi.<\/p>\n Max Plack Enstit\u00fcs\u00fc\u2019nden astrofizik\u00e7i Thavisha Dharmawardena bunun ger\u00e7ekle\u015fmi\u015f olabilece\u011fini d\u00fc\u015f\u00fcnenlerdendi: “Ba\u015fka a\u00e7\u0131klamalar\u0131n da oldu\u011funu biliyorduk ve bunlar\u0131 da incelememiz gerekebilirdi. Ama Betelgeuse\u2019un ya\u015fl\u0131 bir y\u0131ld\u0131z oldu\u011funu da biliyorduk, ya\u015fam\u0131n\u0131n sonuna yak\u0131nd\u0131. Bu durum heyecan vericiydi.”<\/p>\n \u0130ki kamp D\u00fcnyan\u0131n d\u00f6rt bir yan\u0131ndaki (ve tabii uzaydaki) teleskoplardan gelen verilerin incelenmesi s\u00fcreci astronomlar\u0131n iki kampa b\u00f6l\u00fcnmesiyle sonu\u00e7land\u0131. \u0130lk kamptakiler, Betelgeuse\u2019\u00fcn i\u00e7inden d\u0131\u015far\u0131 p\u00fcsk\u00fcrtt\u00fc\u011f\u00fc toz bulutunun kendi parlakl\u0131\u011f\u0131n\u0131 kesti\u011fini s\u00f6ylerken, ikinci kamptakiler ise cevab\u0131n ne oldu\u011fu konusundan emin olmamakla birlikte toz iddias\u0131na \u201chay\u0131r\u201d diyor.<\/p>\n E\u011fer toz bulutu tezi do\u011fru ise, bunun evrendeki karma\u015f\u0131k kimyan\u0131n, gezegenlerin ve hatta ya\u015fam\u0131n k\u00f6keniyle ilgili derin anlamlar\u0131 olabilir. K\u0131rm\u0131z\u0131 s\u00fcper devler sadece y\u0131ld\u0131zlar\u0131n i\u00e7erisinde d\u00f6v\u00fclm\u00fc\u015f olan elementlerle dolu, da\u011f\u0131n\u0131k gaz ve toz bulutlar\u0131 ile \u00e7evrilidir. Bu bulutlar y\u0131ld\u0131z patlamadan \u00f6nce olu\u015fur. G\u00f6r\u00fcn\u00fc\u015fe g\u00f6re s\u00fcper devler \u00f6lmeden \u00f6nce dahi yeni nesil y\u0131ld\u0131zlara bu malzemeleri miras b\u0131rak\u0131rlar. Montarg\u00e8s, \u201cV\u00fccudumuzdaki karbon ve oksijen de oradan gelir, s\u00fcpernovalardan ve \u00f6len y\u0131ld\u0131zlar\u0131n etraf\u0131ndaki bulutlardan\u201d diye belirtiyor. Ancak bu elementlerin y\u0131ld\u0131zlardan d\u0131\u015far\u0131 nas\u0131l ka\u00e7t\u0131\u011f\u0131 hala net de\u011fil. Montarg\u00e8s, Betelgeuse\u2019\u00fcn ilgin\u00e7 davran\u0131\u015f\u0131n\u0131n incelenmesiyle bilim insanlar\u0131n\u0131n bu s\u00fcreci izleyebilmelerinin m\u00fcmk\u00fcn olmas\u0131n\u0131 umuyor.<\/p>\n Aral\u0131k 2019\u2019da o ve meslekta\u015flar\u0131 Betelgeuse\u2019\u00fc g\u00f6r\u00fcn\u00fcr \u0131\u015f\u0131k tayf\u0131nda g\u00f6r\u00fcnt\u00fcledi. Bu \u00e7al\u0131\u015fma \u015eili\u2019deki VLT\u2019nin (Very Large Telescope: \u00c7ok B\u00fcy\u00fck Teleskop) \u00fczerindeki SPHERE enstr\u00fcman\u0131 kullan\u0131larak yap\u0131ld\u0131. Sonu\u00e7lar g\u00f6sterdi ki, Betelgeuse 11 ay \u00f6ncekinden \u00e7ok daha soluktu ancak y\u0131ld\u0131z\u0131n sadece alt yar\u0131s\u0131. Bu da, olay\u0131n sorumlusunun asimetrik bir toz bulutu olmas\u0131 ihtimalini i\u015faret ediyor.<\/p>\n 15 \u015eubat 2020 tarihli g\u00f6zlem verileri bu fikri destekler gibi g\u00f6r\u00fcn\u00fcyor. Bu verileri \u015eubat 2004\u2019teki verilerle kar\u015f\u0131la\u015ft\u0131ran ara\u015ft\u0131rmac\u0131lar, Betelgeuse\u2019\u00fcn s\u0131cakl\u0131\u011f\u0131ndaki d\u00fc\u015f\u00fc\u015f\u00fcn, konveksiyon d\u00f6ng\u00fcleri gibi, y\u0131ld\u0131z\u0131n i\u00e7sel bir durumundan kaynaklanabilecek kadar fazla olmad\u0131\u011f\u0131n\u0131 rapor ettiler (ilgili makale 10 Mart 2020\u2019de Astrophysical Journal Letters\u2019da yay\u0131mland\u0131). Yani toz bulutu tezi ge\u00e7erli bir a\u00e7\u0131klama olarak kald\u0131. Ara\u015ft\u0131rmac\u0131lar, Betelgeuse\u2019un p\u00fcsk\u00fcrtt\u00fc\u011f\u00fc k\u00fctlenin, y\u0131ld\u0131z\u0131n etraf\u0131nda toza neden oldu\u011funun bilindi\u011fini ve bu tozun D\u00fcnyam\u0131z do\u011frultusunda ilerlerken so\u011fuyup, ge\u00e7ici olarak y\u0131ld\u0131z\u0131n \u0131\u015f\u0131\u011f\u0131n\u0131 kesebilece\u011fini belirtiyor.<\/p>\n Kara bulut<\/strong> Dupree, farkl\u0131 \u00fclkelerden ara\u015ft\u0131rmac\u0131lardan olu\u015fan uluslararas\u0131 ekibiyle birlikte Betelgeuse\u2019\u00fc 2019\u2019un sonuna kadar \u2013senede birka\u00e7 kez\u2013 d\u00fczenli bir \u015fekilde g\u00f6zlemledi. Hubble arac\u0131l\u0131\u011f\u0131yla \u00e7e\u015fitli dalga boylar\u0131nda ger\u00e7ekle\u015ftirilen bu g\u00f6zlemlerin amac\u0131 Montarg\u00e8s\u2019inkiyle ayn\u0131yd\u0131; Betelgeuse\u2019\u00fcn ve muhtemelen di\u011fer k\u0131rm\u0131z\u0131 s\u00fcper devlerin i\u00e7lerindeki malzemeyi nas\u0131l kaybettikleri sorusuna cevap bulmak.<\/p>\n Ekibin Ocak ve Mart 2019\u2019daki g\u00f6zlemlerinde Betelgeuse \u201ctamamen normal\u201d g\u00f6r\u00fcn\u00fcrken, s\u00f6n\u00fckle\u015fme olay\u0131n\u0131n ger\u00e7ekle\u015fmesinden hemen \u00f6nce, yani Eyl\u00fcl\u2019den Kas\u0131m\u2019a kadarki s\u00fcre\u00e7te, y\u0131ld\u0131z\u0131n g\u00fcney yar\u0131m k\u00fcresinde normalin d\u00f6rt veya be\u015f kat\u0131 kadar mor\u00f6tesi \u0131\u015f\u0131ma tespit edildi. Ayn\u0131 \u015fekilde, bu b\u00f6lgede s\u0131cakl\u0131k ve elektron yo\u011funlu\u011funun da y\u00fckseldi\u011fi g\u00f6zlendi. Dahas\u0131 y\u0131ld\u0131zsal madde, y\u0131ld\u0131z\u0131n d\u0131\u015f\u0131na do\u011fru \u2013D\u00fcnyam\u0131z do\u011frultusunda\u2013 hareketlenmi\u015f gibi g\u00f6r\u00fcn\u00fcyordu.<\/p>\n Ne oldu\u011funa dair Dupree ve meslekta\u015flar\u0131n\u0131n teorisi, y\u0131ld\u0131z\u0131n d\u0131\u015f katmanlar\u0131nda s\u00fcrekli olarak \u00e7alkalanan dev ve s\u0131cak plazma kabarc\u0131klar\u0131ndan birinin, y\u0131ld\u0131z\u0131n atmosferinin s\u0131n\u0131r\u0131na kadar y\u00fckselip ka\u00e7t\u0131\u011f\u0131 ve b\u00fcy\u00fck miktarda maddeyi y\u0131ld\u0131zlararas\u0131 uzaya sa\u00e7t\u0131\u011f\u0131 y\u00f6n\u00fcnde (ilgili makale 10 A\u011fustos 2020\u2019de Astrophysical Journal\u2019da yay\u0131mland\u0131). Bu olay, k\u0131rm\u0131z\u0131 s\u00fcper devlerin patlamadan \u00f6nce i\u00e7erisindeki malzemeyi yaymas\u0131n\u0131n bir \u00f6rne\u011fi olabilir.<\/p>\n Dupree\u2019ye g\u00f6re, s\u0131cak madde bir kez y\u0131ld\u0131zdan kurtulduktan sonra, so\u011fuyup yo\u011funla\u015farak toz bulutunu meydana getirdi ve birka\u00e7 ayl\u0131\u011f\u0131na Betelgeuse\u2019\u00fcn \u00f6n\u00fcnde y\u00fczd\u00fc. \u00d6n\u00fcndeki toz temizlendik\u00e7e de Betelgeuse parlakl\u0131\u011f\u0131n\u0131 tekrar kazand\u0131. Dupree konuyla ilgili olarak, \u201cBize \u00f6yle geliyor ki, g\u00f6rd\u00fc\u011f\u00fcm\u00fcz mor\u00f6tesi \u0131\u015f\u0131ma, bir t\u00fcr t\u00fcten silah\u201d diyor ve ekliyor, \u201cMalzeme d\u0131\u015far\u0131 do\u011fru ilerledi, yo\u011funla\u015ft\u0131 ve bu kara toz bulutunu olu\u015fturdu\u201d.<\/p>\n Herkes ayn\u0131 fikirde olmasa da, NASA\u2019n\u0131n astrofizik b\u00f6l\u00fcm\u00fc direkt\u00f6r\u00fc Paul Hertz, Hubble\u2019\u0131n sonu\u00e7lar\u0131n\u0131 10 Eyl\u00fcl\u2019de ger\u00e7ekle\u015fen \u00e7evrimi\u00e7i bir toplant\u0131da sunarak, gizemin \u00e7\u00f6z\u00fcld\u00fc\u011f\u00fcn\u00fc duyurdu.<\/p>\n D\u00f6ng\u00fcler ve lekeler<\/strong> Dharmawardena ve meslekta\u015flar\u0131, Hawaii\u2019deki James Clerk Maxwell Teleskopu\u2019nu kullanarak Ocak, \u015eubat ve Mart Aylar\u0131nda milimetre-alt\u0131 dalga boyunda yapt\u0131klar\u0131 g\u00f6zlemlere dayanarak toz bulutu tezine kar\u015f\u0131 \u00e7\u0131k\u0131yor. (\u0130lgili makale 1 Temmuz 2020\u2019de Astrophysical Journal Letters\u2019da yay\u0131mland\u0131). Dharmawardena\u2019ya g\u00f6re, e\u011fer nedenin bir toz bulutu oldu\u011fu d\u00fc\u015f\u00fcn\u00fcl\u00fcyorsa, bak\u0131lmas\u0131 gereken ideal yer milimetre-alt\u0131 dalga boyu, \u00e7\u00fcnk\u00fc toz nedeniyle Betelgeuse bu dalga boyunda daha parlak g\u00f6r\u00fcnmeli. Bunun sebebi y\u00fczen toz zerrelerinin y\u0131ld\u0131zdan gelen \u0131\u015f\u0131\u011f\u0131 emip -\u2013milimetre-alt\u0131 dalga boyunda\u2013 tekrar yaymas\u0131.<\/p>\n Ancak g\u00f6zlemlenen bu de\u011fil; aksine y\u0131ld\u0131z\u0131n milimetre-alt\u0131ndaki parlakl\u0131\u011f\u0131 hafif\u00e7e azalm\u0131\u015f g\u00f6r\u00fcn\u00fcyor. Dharmawardena, ilk d\u00fc\u015f\u00fcncelerinin bir yerlerde hata yapt\u0131klar\u0131 y\u00f6n\u00fcnde oldu\u011funu, \u00e7\u00fcnk\u00fc topluluktaki herkesin toz bulmay\u0131 bekledi\u011fini s\u00f6yl\u00fcyor. Ancak parlakl\u0131\u011f\u0131n milimetre-alt\u0131nda \u201cne artm\u0131\u015f ne de sabit kalm\u0131\u015f olmas\u0131 ger\u00e7e\u011fi\u201dnin bunun toz olmad\u0131\u011f\u0131n\u0131 a\u00e7\u0131k\u00e7a ortaya koydu\u011funu belirtiyor.<\/p>\n E\u011fer toz ger\u00e7ekten varsa, u\u00e7akla ta\u015f\u0131nan SOFIA teleskopuyla k\u0131z\u0131l\u00f6tesi dalga boylar\u0131nda yap\u0131lan g\u00f6zlemlerde de \u0131\u015f\u0131yan tozun izine rastlanmal\u0131yd\u0131. Ancak burada da tozun varl\u0131\u011f\u0131na dair bir kan\u0131t bulunamad\u0131.<\/p>\n Guinan, Betelgeuse\u2019daki s\u00f6n\u00fckle\u015fmenin y\u0131ld\u0131z\u0131n do\u011fal konveksiyon d\u00f6ng\u00fcs\u00fcn\u00fcn bir par\u00e7as\u0131 olabilece\u011fini d\u00fc\u015f\u00fcn\u00fcyor. Y\u0131ld\u0131z\u0131n i\u00e7erisindeki devasa s\u0131cak plazma kabarc\u0131klar\u0131, y\u00fczeye y\u00fckselip gerisin geri batarak, d\u0131\u015f atmosferin d\u00fczenli bir \u015fekilde zonklamas\u0131na, Guinan\u2019\u0131n tabiriyle \u201cnefes al\u0131p vermesine\u201d neden olur. Guinan, y\u0131ld\u0131z\u0131n i\u00e7 \u00e7ekirde\u011finin burada motor i\u015flevi g\u00f6rd\u00fc\u011f\u00fcn\u00fc belirtiyor, \u201ci\u00e7 katmanlardan y\u00fckselen k\u00fctle so\u011fuyup yo\u011funla\u015farak geri d\u00fc\u015f\u00fcyor\u201d.<\/p>\n \u00c7ak\u0131\u015fan birden fazla d\u00f6ng\u00fc 2019\u2019daki s\u00f6n\u00fckle\u015fmenin neden bu kadar \u015fiddetli oldu\u011funu a\u00e7\u0131klayabilir. Guinan ve meslekta\u015flar\u0131 Betelgeuse\u2019un \u2013tarihi, John Herschel\u2019in y\u0131ld\u0131z\u0131n parlakl\u0131\u011f\u0131ndaki de\u011fi\u015fimi ke\u015ffetti\u011fi 1839\u2019a kadar uzanan\u2013 180 y\u0131ll\u0131k g\u00f6zlem ge\u00e7mi\u015fini analiz ettiler. Ekip, y\u0131ld\u0131z\u0131n halihaz\u0131rda bilinen yakla\u015f\u0131k 6 y\u0131ll\u0131k ve 400 g\u00fcnl\u00fck d\u00f6ng\u00fclerine ek olarak, \u00fc\u00e7\u00fcnc\u00fc ve daha k\u0131sa aral\u0131kl\u0131 (187 g\u00fcnl\u00fck) bir d\u00f6ng\u00fcs\u00fc daha olabilece\u011fini ke\u015ffettiler. Guinan, g\u00f6r\u00fcn\u00fc\u015fe bak\u0131l\u0131rsa 2019\u2019un sonralar\u0131nda bu \u00fc\u00e7 d\u00f6ng\u00fcn\u00fcn de en d\u00fc\u015f\u00fck patlakl\u0131k noktas\u0131n\u0131n \u00e7ak\u0131\u015fm\u0131\u015f olabilece\u011fini s\u00f6yl\u00fcyor.<\/p>\n Dharmawardena\u2019n\u0131n g\u00f6r\u00fc\u015f\u00fc ise, Montarg\u00e8s\u2019in ekibinin SPHERE ile g\u00fcney yar\u0131m k\u00fcrede g\u00f6rd\u00fc\u011f\u00fc karart\u0131n\u0131n nedeninin dev bir y\u0131ld\u0131z lekesi olabilece\u011fi y\u00f6n\u00fcnde. G\u00fcne\u015f\u2019te de g\u00f6r\u00fclen bu kara benekler (G\u00fcne\u015f lekeleri), y\u00fczeydeki manyetik olarak aktif b\u00f6lgelerin i\u015faret\u00e7isidir. Betelgeuse\u2019\u00fcn, y\u0131ld\u0131z lekelerinin D\u00fcnya\u2019dan direkt olarak se\u00e7ilebildi\u011fi bir avu\u00e7 y\u0131ld\u0131zdan biri oldu\u011funu da belirtelim.<\/p>\n Ancak Betelgeuse\u2019daki s\u00f6n\u00fckle\u015fmeye neden olmas\u0131 i\u00e7in, y\u0131ld\u0131z lekesinin devasa boyutlarda olmas\u0131 gerekir. Dharmawardena, tipik y\u0131ld\u0131z lekelerinin y\u0131ld\u0131z\u0131n \u2013g\u00f6r\u00fcnen\u2013 y\u00fczeyinin yakla\u015f\u0131k y\u00fczde 20 ila 30\u2019unu kaplad\u0131\u011f\u0131n\u0131 belirtiyor. Betelgeuse\u2019dakinin ise en az yar\u0131s\u0131n\u0131 (belki y\u00fczde 70\u2019ine kadar) kaplamas\u0131 gerekiyor. Dharmawardena bunun nadir g\u00f6r\u00fclen bir durum olaca\u011f\u0131n\u0131 kabul etmekle beraber, Betelgeuse\u2019daki s\u00f6n\u00fckle\u015fmenin a\u00e7\u0131klamas\u0131 olabilece\u011fini d\u00fc\u015f\u00fcn\u00fcyor.<\/p>\n Pandemi engeli<\/strong> Dharmawardena, \u201c\u00c7ok daha fazla veriye sahip olmay\u0131 umuyorduk\u201d diyor.<\/p>\n Birka\u00e7 g\u00f6zlem son dakikada yeti\u015fti. SOFIA ile yap\u0131lan g\u00f6zlemeler pandemi nedeniyle u\u00e7u\u015f k\u0131s\u0131tlamalar\u0131 gelmeden \u00f6nce yap\u0131lan son u\u00e7u\u015flardan oldu. Montarg\u00e8s de, g\u00f6zlemevi Mart Ay\u0131n\u0131n ortas\u0131nda kapanmadan birka\u00e7 g\u00fcn \u00f6nce SPHERE ile son g\u00f6zlemlerini yapt\u0131.<\/p>\n Montarg\u00e8s\u2019e g\u00f6re, cevab\u0131n toz olup olmad\u0131\u011f\u0131n\u0131 \u00e7\u00f6zmenin en umut vaat eden yolu, Dupree\u2019nin 90\u2019l\u0131 y\u0131llarda Hubble ile yapt\u0131\u011f\u0131 gibi y\u0131ld\u0131z\u0131n t\u00fcm diskinin 2 boyutlu bir g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fcn olu\u015fturulmas\u0131, ama bu sefer k\u0131z\u0131l\u00f6tesi veya milimetre-alt\u0131 gibi daha uzun dalga boylar\u0131nda; t\u0131pk\u0131 Dharmawardena\u2019n\u0131n 2020\u2019nin ba\u015f\u0131nda olu\u015fturdu\u011fu g\u00f6r\u00fcnt\u00fcler gibi. Montarg\u00e8s bu sayede tozun y\u0131ld\u0131zdan ay\u0131rt edilebilece\u011fini d\u00fc\u015f\u00fcn\u00fcyor.<\/p>\n Sadece tek bir g\u00f6zlemevi bu ikisini birlikte ger\u00e7ekle\u015ftirebilir: \u015eili\u2019deki Atacama \u00c7\u00f6l\u00fc’nde bulunan ALMA (Atacama Large Millimeter\/submillimeter Array: Atacama B\u00fcy\u00fck Milimetre\/Milimetre-alt\u0131 Dizgesi). Montarg\u00e8s, Haziran ve Temmuz aylar\u0131nda (g\u00fcney yar\u0131m k\u00fcrede k\u0131\u015f\u0131n g\u00f6ky\u00fcz\u00fcn\u00fcn en duru oldu\u011fu d\u00f6nemde) ALMA\u2019y\u0131 kullanarak Betelgeuse\u2019\u00fc g\u00f6zlemlemek i\u00e7in ba\u015fvuruda bulunmay\u0131 planlarken, g\u00f6zlemevi Mart Ay\u0131nda pandemi nedeniyle kapand\u0131. F\u0131rsat ka\u00e7m\u0131\u015ft\u0131 ve Montarg\u00e8s\u2019e g\u00f6re belki cevab\u0131 bulma umudu da.<\/p>\n Ba\u015fka herhangi bir y\u0131ld\u0131z Bu arada, Montarg\u00e8s en sevdi\u011fi y\u0131ld\u0131z\u0131n yeniden eskisi gibi par\u0131ldad\u0131\u011f\u0131n\u0131 g\u00f6rmekten memnum g\u00f6r\u00fcn\u00fcyor, \u201cKabul etmeliyim ki (2019) Aral\u0131k ay\u0131ndan, yani t\u00fcm bunlar ba\u015flad\u0131\u011f\u0131ndan beri, onu her g\u00f6rd\u00fc\u011f\u00fcmde, ‘Vay be, i\u015fte hala orada’ diyorum\u201d diyor.<\/p>\n \u0130nsanlar ona s\u00fcrekli Betelgeuse\u2019\u00fcn s\u00fcpernova ge\u00e7irmesini isteyip istemedi\u011fi soruyor, sonu\u00e7ta \u00fczerinde \u00e7al\u0131\u015fabilece\u011fi bir konu olacak bu. Montarg\u00e8s, \u201cBa\u015fka herhangi bir y\u0131ld\u0131z\u0131n s\u00fcpernova ge\u00e7irmesini isterim\u201d diyor ve ekliyor: \u201c(Mesela) Antares, onu hi\u00e7 umursam\u0131yorum; istedi\u011fi zaman patlayabilir. Ama Betelgeuse de\u011fil.”<\/p>\n Kaynak:<\/strong> https:\/\/www.sciencenews.org\/article\/betelgeuse-star-dim-supernova-death-what-happened<\/p>\n","protected":false},"excerpt":{"rendered":" Astrofizik\u00e7i Miguel Montarg\u00e8s, Betelgeuse ile tan\u0131\u015ft\u0131\u011f\u0131 an\u0131 h\u00e2l\u00e2 net bir \u015fekilde hat\u0131rl\u0131yor. 7-8 ya\u015flar\u0131ndayd\u0131, ailesinin Fransa\u2019n\u0131n g\u00fcneyindeki evinin bah\u00e7esinden g\u00f6ky\u00fcz\u00fcne bak\u0131yordu. Bir an parlak ve k\u0131rm\u0131z\u0131 bir y\u0131ld\u0131z gecenin karanl\u0131\u011f\u0131nda g\u00f6z k\u0131rpt\u0131. Minik uzay merakl\u0131s\u0131 o s\u0131ralar inceledi\u011fi astronomi dergisinden \u00e7\u0131kan y\u0131ld\u0131z haritas\u0131nda o y\u0131ld\u0131z\u0131 buldu, ismi Betelgeuse\u2019d\u00fc. Bu ke\u015fif zihnini ayd\u0131nlatm\u0131\u015ft\u0131. O y\u0131ld\u0131z art\u0131k […]<\/p>\n","protected":false},"author":677,"featured_media":48245,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19],"tags":[7249,7250,2300,1845,1780],"class_list":["post-48243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","tag-betelgeuse","tag-parlaklik","tag-supernova","tag-teleskop","tag-yildiz"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t
\nE\u011fer k\u0131\u015f\u0131n Kuzey Yar\u0131m K\u00fcre’den g\u00f6ky\u00fcz\u00fcne bakt\u0131ysan\u0131z, \u2013o oldu\u011funu fark etmemi\u015f olsan\u0131z dahi\u2013 muhtemelen Betelgeuse\u2019\u00fc g\u00f6rm\u00fc\u015fs\u00fcn\u00fczd\u00fcr. Betelgeuse, Orion (Avc\u0131) Tak\u0131my\u0131ld\u0131z\u0131 i\u00e7erisindeki ikinci en parlak y\u0131ld\u0131zd\u0131r; bak\u0131\u015f a\u00e7\u0131m\u0131za g\u00f6re avc\u0131n\u0131n sol omzunu i\u015faretler.<\/p>\n![\"\"](\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2021\/01\/orion.jpg\")
\n\u015eunu da belirtmek gerekir ki, Betelgeuse sonunda patlad\u0131\u011f\u0131nda D\u00fcnya\u2019daki ya\u015fama zarar vermesi beklenmiyor, y\u0131ld\u0131z D\u00fcnyam\u0131zdan g\u00fcvenli bir uzakl\u0131\u011fa sahip. Dolay\u0131s\u0131yla meselenin g\u00fcvenlik boyutu s\u00f6z konusu de\u011fil.<\/p>\n![\"\"](\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2021\/01\/astrofizik.jpg\")
\n<\/strong>\u015eubat ay\u0131n\u0131n ortalar\u0131nda y\u0131ld\u0131z her zamanki parlakl\u0131\u011f\u0131na d\u00f6nmeye ba\u015flay\u0131nca, s\u00fcpernova tart\u0131\u015fmalar\u0131 da duruldu. 10 Ekim\u2019de Astrophysical Journal<\/em>\u2019da yay\u0131mlanan bir makale Betelgeuse\u2019\u00fcn ya\u015fl\u0131l\u0131k d\u00f6neminin daha ba\u015f\u0131nda oldu\u011funu ve patlayana kadar daha en az 100.000 y\u0131l\u0131 daha oldu\u011funu \u00f6ng\u00f6r\u00fcyordu. Yani Betelgeuse sa\u011f salim yerinde durmaya devam edecekti. \u00d6yleyse bu g\u00f6zlenenlere ne sebep olmu\u015ftu?<\/p>\n![\"\"](\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2021\/01\/Betelgeuse-1.jpg\")
![\"\"](\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2021\/01\/Betelgeuse-2.jpg\")
\nToz bulutuna g\u00fc\u00e7l\u00fc bir destek, Betelgeuse\u2019\u00fc Hubble Uzay Teleskopu\u2019yla izleyen Dupree\u2019den geldi; Guinan gibi onun da Betelgeuse ile on y\u0131llard\u0131r s\u00fcr\u00fcp giden bir ili\u015fkisi var. 1996\u2019da Dupree ve meslekta\u015f\u0131 Ronald Gilliland Hubble ile Betelgeuse\u2019a odaklanarak y\u0131ld\u0131z\u0131n g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc ilk yakalayan ki\u015filer oldular. Bu g\u00f6r\u00fcnt\u00fc ayn\u0131 zamanda G\u00fcne\u015f d\u0131\u015f\u0131ndaki bir y\u0131ld\u0131za ait ilk g\u00f6r\u00fcnt\u00fc olmas\u0131 a\u00e7\u0131s\u0131ndan da \u00f6nemli. \u00c7o\u011fu y\u0131ld\u0131z bizden olduk\u00e7a uzak ve d\u00fc\u015f\u00fck patlakl\u0131ktad\u0131r, dolay\u0131s\u0131yla uzayda yaln\u0131zca bir nokta gibi g\u00f6r\u00fcn\u00fcrler. Betelgeuse ise y\u00fczeyi iki boyutlu bir disk olarak g\u00f6r\u00fcnt\u00fclenebilen nadir y\u0131ld\u0131zlardand\u0131r.<\/p>\n
\nBetelgeuse s\u00fcpernova ge\u00e7irmeyecek olabilir, ancak bu, toz bulutunun s\u00f6n\u00fckle\u015fmenin ard\u0131ndaki esas neden oldu\u011fu anlam\u0131na da gelmemektedir.<\/p>\n
\nAnaliz sonu\u00e7lar\u0131 gelmeyi s\u00fcrd\u00fcr\u00fcyor. Ancak tam Betelgeuse normal parlakl\u0131\u011f\u0131na d\u00f6nd\u00fc\u011f\u00fc s\u0131ralar b\u00fct\u00fcn d\u00fcnyay\u0131 COVID-19 pandemisi vurdu.<\/p>\n
\n<\/strong>Sonu\u00e7ta Montarg\u00e8s\u2019e g\u00f6re, e\u011fer toz bulutu kamp\u0131nda yer alanlar k\u0131smen de olsa hakl\u0131 iseler, Betelgeuse\u2019\u00fcn s\u00f6n\u00fckle\u015fmesi ile birlikte ya\u015fam\u0131n temeli olan malzemenin evrene yay\u0131l\u0131\u015f\u0131n\u0131 ilk kez canl\u0131 olarak izlemi\u015f olabiliriz. Bu, evrendeki ya\u015fam\u0131n k\u00f6kenini anlamak a\u00e7\u0131s\u0131ndan e\u011fitici olabilir.<\/p>\n