NASA\u2019n\u0131n Washington DC kentinde bulunan G\u00fcne\u015f Fizi\u011fi Bilim Birimi direkt\u00f6r\u00fc Nicola Fox, 14 Aral\u0131k\u2019ta Amerikan Jeofizik Birli\u011fi\u2019nin sonbahar toplant\u0131s\u0131nda \u201cSonunda geldik\u201d diyerek g\u00fczel haberi duyurdu: \u201c\u0130nsanl\u0131k G\u00fcne\u015f’e dokundu.\u201d
\nNASA taraf\u0131ndan \u00fcretilen ve kontrol edilen Parker G\u00fcne\u015f Sondas\u0131, 28 Nisan 2021\u2019de g\u00fcne\u015fle yak\u0131n rastla\u015fmalar\u0131ndan birinde gezegenler aras\u0131 uzaydan ayr\u0131ld\u0131 ve G\u00fcne\u015f’i kapsayan alan\u0131n i\u00e7inden ge\u00e7ti. Oradayken de Alfv\u00e9 kritik y\u00fczeyi olarak adland\u0131r\u0131lan G\u00fcne\u015f atmosferi s\u0131n\u0131r\u0131n\u0131n tam olarak nerede oldu\u011funu g\u00f6steren ilk \u00f6l\u00e7\u00fcmleri yapt\u0131.<\/p>\n
Alfv\u00e9n kritik y\u00fczeyinin var olmas\u0131 gerekti\u011fini biliyorduk\u201d diyor Ann Arbor\u2019daki Michigan \u00dcniversitesi\u2019nden G\u00fcne\u015f fizik\u00e7isi Justin Kasper. \u201cSadece tam nerede oldu\u011funu bilmiyorduk. 2018\u2019de f\u0131rlat\u0131ld\u0131\u011f\u0131nda G\u00fcne\u015f katmanlar\u0131n\u0131n tam konumlar\u0131n\u0131 bulmak Parker G\u00fcne\u015f sondas\u0131n\u0131n birincil hedeflerinden biriydi. Alfv\u00e9n kritik y\u00fczeyi \u00f6nemli \u00e7\u00fcnk\u00fc bu b\u00f6lge, plazma paketlerinin G\u00fcne\u015f’ten ayr\u0131l\u0131p G\u00fcne\u015f r\u00fczgar\u0131n\u0131n par\u00e7as\u0131 haline geldi\u011fi bokta ve s\u00fcrekli olarak g\u00fcne\u015ften yay\u0131lan y\u00fckl\u00fc par\u00e7ac\u0131klar\u0131n h\u0131zl\u0131 ak\u0131nt\u0131lar\u0131n\u0131 ba\u015flad\u0131\u011f\u0131 nokta. G\u00fcne\u015f r\u00fczgar\u0131 ve daha dramatik di\u011fer uzay hava durumu etkenleri, D\u00fcnya\u2019n\u0131n uydular\u0131nda ve hatta gezegenimizdeki ya\u015fama bile y\u0131k\u0131c\u0131 etkilere sebep olabilirler. Biliminsanlar\u0131 G\u00fcne\u015f r\u00fczgarlar\u0131n\u0131n D\u00fcnya\u2019y\u0131 nas\u0131l etkileyece\u011fini daha iyi anlamak i\u00e7in bu r\u00fczgar\u0131n nas\u0131l ba\u015flad\u0131\u011f\u0131n\u0131 tam olarak belirlemek istiyor.
\nAyr\u0131ca Alfv\u00e9n kritik y\u00fczeyi en b\u00fcy\u00fck g\u00fcne\u015f gizemlerinden birinin anahtar\u0131 olabilir: Neden G\u00fcne\u015f’in “korona”s\u0131(incecik d\u0131\u015f atmosferi, G\u00fcne\u015f halesi veya tac\u0131 da denir) G\u00fcne\u015f’in y\u00fczeyinden daha s\u0131cak?<\/p>\n
Bir\u00e7ok \u0131s\u0131 kayna\u011f\u0131nda, \u0131s\u0131y\u0131y\u0131 esas yayan \u00e7ekirdekten uzakla\u015ft\u0131k\u00e7a s\u0131cakl\u0131k d\u00fc\u015fer ama G\u00fcne\u015f’in “y\u00fczeyi” binlerce derece s\u0131cakl\u0131ktayken G\u00fcne\u015f koronas\u0131, milyonlarca s\u0131cakl\u0131ktan fazlas\u0131na ula\u015fabilir. 1942\u2019de fizik\u00e7i Hannes Alfv\u00e9n bu gizeme bir \u00e7\u00f6z\u00fcm \u00f6nerdi, bir manyetik dalga tipi G\u00fcne\u015f y\u00fczeyinden enerji ta\u015f\u0131yor ve koronay\u0131 \u0131s\u0131t\u0131yor. Alt koronada bu t\u00fcr dalgalar\u0131 do\u011frudan g\u00f6zlemlemek 2009\u2019da m\u00fcmk\u00fcn oldu ancak g\u00f6zlenen dalgalar\u0131n, koronadaki t\u00fcm \u0131s\u0131y\u0131 a\u00e7\u0131klamak i\u00e7in yeterli enerjiyi olu\u015fturmad\u0131\u011f\u0131 g\u00f6r\u00fcld\u00fc. G\u00fcne\u015f fizik\u00e7ileri bu t\u00fcr dalgalar y\u00fckseklere t\u0131rmand\u0131\u011f\u0131nda ve Alfv\u00e9n kritik y\u00fczeyiyle bulu\u015ftu\u011funda koronay\u0131 \u0131s\u0131tmak i\u00e7in bir rol oynayabilece\u011finden \u015f\u00fcphelendi. \u015eimdiye kadar biliminsanlar\u0131 bu s\u0131n\u0131r\u0131n nerede ba\u015flay\u0131p bitti\u011fini bilmiyor ve bu s\u0131n\u0131rlar\u0131n tespit edilmesiyle koronal \u0131s\u0131n\u0131n nas\u0131l oldu\u011funa \u015fimdi tan\u0131kl\u0131k edebilece\u011fimizi belirtiyor Justin Kasper.<\/p>\n
Parker sondas\u0131, bu g\u00f6r\u00fcnmez s\u0131n\u0131rlardan ge\u00e7ti\u011fi zaman, yerel manyetik alan\u0131n g\u00fcc\u00fcnde i\u015faretlenmi\u015f bir y\u00fckseli\u015fi ve y\u00fcklenmi\u015f maddenin yo\u011funlu\u011funda bir d\u00fc\u015f\u00fc\u015f kaydetti. Solar r\u00fczgar\u0131nda, y\u00fckl\u00fc par\u00e7ac\u0131k dalgalar\u0131 g\u00fcne\u015ften ayr\u0131ld\u0131. Alfv\u00e9n kritik y\u00fczeyinin alt\u0131nda bu dalgalar\u0131n baz\u0131lar\u0131 g\u00fcne\u015fin y\u00fczeyine do\u011fru b\u00fck\u00fcl\u00fcr.
\nS\u00fcrpriz bir \u015fekilde Parker\u2019\u0131n hesaplamalar\u0131 g\u00f6sterdi ki Alfv\u00e9n kritik y\u00fczeyi d\u00fcz de\u011fil “buru\u015fuk”.G\u00fcne\u015f fizik\u00e7isi Craig DeForest, Alfv\u00e9n y\u00fczeyin var olup olmad\u0131\u011f\u0131 konusunda dahi tart\u0131\u015fmalar oldu\u011funu hat\u0131rlatarak, bu y\u00fczeyin var olmas\u0131n\u0131n yan\u0131s\u0131ra bir de beklenmeyen \u015fekline dikkat \u00e7ekiyor. Biliminsanlar\u0131 \u00f6nceden G\u00fcne\u015f’in etraf\u0131nda onu kar k\u00fcresi gibi saran bir yap\u0131 d\u00fc\u015f\u00fcn\u00fcyorlard\u0131. Modern zamanlardaysa Parker sondas\u0131n\u0131n bu y\u00fczeyin i\u00e7inden ge\u00e7ti\u011fini anlamyaca\u011f\u0131 kadar ince ve \u015feffaf oldu\u011funu d\u00fc\u015f\u00fcn\u00fcyorlard\u0131. \u00c7o\u011fu ki\u015finin bu konularda yan\u0131ld\u0131\u011f\u0131n\u0131 s\u00f6ylemek abart\u0131 olmaz.<\/p>\n
Parker sondas\u0131n\u0131n yapt\u0131\u011f\u0131 ke\u015ffe bak\u0131l\u0131rsa y\u00fczey, ge\u00e7i\u015fin fark edilmesi i\u00e7in yeterince p\u00fcr\u00fczs\u00fcz ama Dr. Kasper, Nisan ay\u0131 boyunca sondan\u0131n G\u00fcne\u015fe yak\u0131n ge\u00e7i\u015fi s\u0131ras\u0131nda s\u0131n\u0131ra 3 kere girip \u00e7\u0131kt\u0131\u011f\u0131n\u0131 belirtiyor. \u0130lk dal\u0131\u015f yakla\u015f\u0131k 5 saat s\u00fcrd\u00fc, son dal\u0131\u015f sadece yar\u0131m saat. “Bu durum bize a\u00e7\u0131k\u00e7a g\u00f6steriyor ki bu yap\u0131 her y\u00f6n\u00fc e\u015fit sarm\u0131yor” diye ekliyor Dr. Kasper.<\/p>\n
Parker sondas\u0131 halen G\u00fcne\u015f etraf\u0131nda d\u00f6nmekte ve \u00f6n\u00fcm\u00fczdeki birka\u00e7 y\u0131l i\u00e7inde birka\u00e7 defa daha G\u00fcne\u015f’in atmosferine dal\u0131\u015flar yapmay\u0131 planl\u0131yor. Yapt\u0131\u011f\u0131 her dal\u0131\u015fta G\u00fcne\u015f’in y\u00fczeyinin yakla\u015f\u0131k 6 milyon kilometre kadar yak\u0131n\u0131na ula\u015f\u0131yor. G\u00fcne\u015f fizik\u00e7isi Nour Raouafi bu dal\u0131\u015flar\u0131n Parker\u2019\u0131 tekrar tekrar G\u00fcne\u015f koronas\u0131na sokmas\u0131n\u0131 beklediklerini s\u00f6yledi. Uzay arac\u0131, a\u011fustos ay\u0131nda Alfv\u00e9n kritik y\u00fczeyini ge\u00e7erek ba\u015fka bir yolculuk daha yapm\u0131\u015f olabilir. Raouafi, \u201cBeklentimiz, Parker G\u00fcne\u015f’e daha yak\u0131n u\u00e7tuk\u00e7a bu s\u0131n\u0131r\u0131 ge\u00e7meye devam etmesi\u201d diyor ancak s\u0131n\u0131r her seferinde ayn\u0131 yerde olmayabilir. G\u00fcne\u015f’in aktivitesi de\u011fi\u015ftik\u00e7e, Alfv\u00e9n kritik y\u00fczeyinin seviyesinin korona nefes al\u0131p veriyormu\u015f gibi y\u00fckselmesi ve d\u00fc\u015fmesi bekleniyor. Bu durum da biliminsanlar\u0131n\u0131n ilk kez g\u00f6zlemlemeyi umduklar\u0131 bir ba\u015fka \u015fey.<\/p>\n
KAYNAK<\/strong><\/p>\n