Galaksi spiral: Pabidaan ralatan

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Volstand (pandir | sumbangan)
Kadada kasimpulan babakan
Volstand (pandir | sumbangan)
Kadada kasimpulan babakan
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[[File:M101 hires STScI-PRC2006-10a.jpg|thumb|Contoh galaksi spiral, An example of a spiral galaxy, [[Galaksj kincir]] (dipinandui jua lawan ngaran Messier 101 atawa NGC 5457)|285x285px]]
 
'''Galaksi spiral''' mambantuk [[klasifikasi morfologi galaksi|kelas matan galakskgalaksi]] nang pamulaannya dijalasakan ulih [[Edwin Hubble]] di buku nang ditulisnya pas tahun 1936 nang bajudul ''The Realm of the Nebulae''<ref name="Hubble-1936">{{cite book|url=https://books.google.com/books?id=kgiXdDGLpFUC|title=The realm of the nebulae|last=Hubble|first=E.P.|publisher=[[Yale University Press]]|year=1936|isbn=9780300025002|series=Mrs. Hepsa Ely Silliman memorial lectures, 25|location=New Haven|oclc=611263346|author-link=Edwin Hubble}} [https://archive.org/details/TheRealmOfTheNebulae Alt URL](pp.&nbsp;124–151)</ref> and,wan asmaulah such,bagian form part of thematan [[Hubblesistim sequenceklasifikasi Hubble]]. MostKabanyakannya, spiralgalaksi galaxies consist ofspiral abantuknya flatrata, rotatingbaputar kaya [[DiscCakram (galaxygalaksi)|diskcakram]], containingbaisi [[starbintang]]s, [[InterstellarAwan mediumantar bintang|gas andwan dustdabu]], andwan ahintinya centralnang concentrationmarupakan ofgabungan starsbintang-bintang knownnang asbanyak thenang biasanya dipinandui lawan ngaran [[BulgeTonjolan (astronomy)|bulgeTonjolan]]. TheseGalaksi arenhinj oftenbiasanya surroundeddikalilingi byjua a much fainterlawan [[GalacticHalo halogalaksi|halo]] ofnang starstakadap matan bintang-bintang, manykabanyakannya ofgalaksi whichngini residebaandak indi [[globulargugus clusterbola]]s.
 
Galaksi spiral dingarani sasuia lawan struktur spiralnya nang bapanjang mulai hinti sampai ka cakram galaksinya. Tangan matan galaksi spiral marupakan tampat formasi bintang nang hanyar wan tatarang pada cakram di sakulilingnya maraga [[Bintang OB]] masih anum, wan panas baandak disana.
Spiral galaxies are named by their spiral structures that extend from the center into the galactic disc. The spiral arms are sites of ongoing star formation and are brighter than the surrounding disc because of the young, hot [[OB star]]s that inhabit them.
 
Roughly two-thirds of all spirals are observed to have an additional component in the form of a bar-like structure,<ref name="mihalas1968">{{Cite book| author=D. Mihalas | date=1968 | title=Galactic Astronomy | publisher=W. H. Freeman | isbn=978-0-7167-0326-6}}</ref> extending from the central bulge, at the ends of which the spiral arms begin. The proportion of [[Barred spiral galaxy|barred spirals]] relative to [[Unbarred spiral galaxy|barless spirals]] has likely changed over the history of the [[universe]], with only about 10% containing bars about 8&nbsp;billion years ago, to roughly a quarter 2.5&nbsp;billion years ago, until present, where over two-thirds of the [[galaxy|galaxies]] in the visible universe ([[Hubble volume]]) have bars.<ref>{{cite web |url= https://www.sciencedaily.com/releases/2014/01/140116085103.htm |title= Hubble and Galaxy Zoo Find Bars and Baby Galaxies Don't Mix |date= 16 January 2014 |website= [[Science Daily]] }}</ref>