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Astronomy Picture of the Day
Posted By admin On April 25, 2011 @ 10:37 pm In Photo Essays | Comments Disabled
A satellite galaxy of our own Milky Way, the Large Magellanic Cloud (LMC) is an alluring sight [1] in dark southern skies and the constellation Dorado [2].
Hydrogen in the LMC
Credit & Copyright [4]: Marco Lorenzi (Star Echoes [5])
Explanation: A satellite galaxy of our own Milky Way, the Large Magellanic Cloud (LMC) is an alluring sight [1] in dark southern skies and the constellation Dorado [2]. A mere 180,000 light-years distant, the LMC is seen in amazing detail in this very deep 4 frame mosaic [6] of telescopic images, a view that reveals the Milky Way’s satellite [7] to have the appearance of a fledgling barred spiral galaxy [8]. The mosaic includes image data taken through a narrow filter that transmits only the red light of hydrogen atoms. Ionized [9] by energetic starlight, a hydrogen atom emits the characteristic red H-alpha [10] light as its single electron is recaptured and transitions to lower energy states. As a result, this mosaic seems spattered with pinkish clouds of hydrogen gas surrounding massive, young stars. Sculpted by the strong stellar winds and ultraviolet radiation, the glowing hydrogen clouds [11] are known as H II [12] (ionized hydrogen) regions. Composed of many overlapping clouds, the sprawling Tarantula Nebula [13] left of center, is by far the LMC’s largest star forming region. The Large Magellanic Cloud is about 15,000 light-years across.
Visit the NASA/JPL website to view more Astronomy Pictures of the Day [14]
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URL to article: http://www.berthoudrecorder.com/2011/04/25/astronomy-picture-of-the-day-62/
URLs in this post:
[1] alluring sight: http://apod.nasa.gov/apod/ap081219.html
[2] Dorado: http://www.hawastsoc.org/deepsky/dor/
[3] Image: http://www.berthoudrecorder.com/wp-content/uploads/2011/04/LMC_HaOIIILRGB_lorenzi2000c.jpg
[4] Copyright: http://apod.nasa.gov/apod/lib/about_apod.html#srapply
[5] Star Echoes: http://astrosurf.com/lorenzi/index.htm
[6] very deep 4 frame mosaic: http://astrosurf.com/lorenzi/ccd/LMC_HaOIIILRGB.htm
[7] Milky Way’s satellite: http://www.atlasoftheuniverse.com/sattelit.html
[8] barred spiral galaxy: http://apod.nasa.gov/apod/ap100820.html
[9] Ionized: http://csep10.phys.utk.edu/astr162/lect/light/ionization.html
[10] H-alpha: http://en.wikipedia.org/wiki/H-alpha
[11] hydrogen clouds: http://csep10.phys.utk.edu/astr162/lect/milkyway/ism.html
[12] H II: http://astrosun2.astro.cornell.edu/academics/courses//astro201/stromgren_sphere.htm
[13] Tarantula Nebula: http://apod.nasa.gov/apod/ap110111.html
[14] Astronomy Pictures of the Day: http://antwrp.gsfc.nasa.gov/apod/
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