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Magellanic Clouds
Magellanic Clouds , two dwarf galaxies located in the far southern sky and visible to the unaided eye; they are classified as irregular because they show no definite symmetry or nucleus. The larger of the two, known as the Large Magellanic Cloud (LMC), is located mostly in the constellation Dorado; its angular diameter measures approximately 7°. The Small Cloud (SMC) is almost completely in the constellation Tucana, and measures approx. 4° in diameter. Both are nearly 160,000 light-years from the earth. They are part of the Local Group of galaxies, which includes our own galaxy (the Milky Way ) and the Andromeda Galaxy , and are the nearest extragalactic objects. The Magellanic Clouds, named for the Portuguese navigator Magellan, were first studied in detail by Sir John Herschel in the 19th cent. While studying Cepheid variable stars in the SMC, Henrietta Leavitt discovered (1912) the period-luminosity relation. This relation offered a technique for measuring the distances of stars and galaxies. In Feb., 1987, Supernova 1987A erupted in the LMC. The first supernova visible without a telescope since 1604, this star gradually brightened over the next few months and remains under careful observation as it fades. The diffuse nebulae in both the LMC and the SMC appear to have fewer "metals" (elements heavier than helium); the deficiency is much more pronounced in the SMC. |
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"Magellanic Clouds." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "Magellanic Clouds." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1E1-MagellaCl.html "Magellanic Clouds." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-MagellaCl.html |
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Magellanic Clouds
Magellanic Clouds The two irregular galaxies that are satellites of our own Galaxy, easily seen with the naked eye in the southern hemisphere like detached portions of the Milky Way. They are named after the Portuguese explorer Ferdinand Magellan (1480–1521), who described them during his voyage around the world. Both Clouds are believed to orbit our Galaxy in a plane nearly perpendicular to its disk, and may eventually spiral into the Galaxy. See also Large Magellanic Cloud; Magellanic Stream; Small Magellanic Cloud.
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"Magellanic Clouds." A Dictionary of Astronomy. 1997. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "Magellanic Clouds." A Dictionary of Astronomy. 1997. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O80-MagellanicClouds.html "Magellanic Clouds." A Dictionary of Astronomy. 1997. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-MagellanicClouds.html |
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Magellanic Clouds
Magellanic Clouds Two satellite galaxies of the Milky Way, visible in skies around the South Pole as misty stellar concentrations. The Small Cloud (Nubecula Minor), located in the constellation of Tucana, is irregular; the Large Cloud (Nubecula Major), mostly in the constellation of Dorado, is vaguely spiral. Their distance is c.150,000 light-years away. See also galaxy
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"Magellanic Clouds." World Encyclopedia. 2005. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "Magellanic Clouds." World Encyclopedia. 2005. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O142-MagellanicClouds.html "Magellanic Clouds." World Encyclopedia. 2005. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-MagellanicClouds.html |
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magellanic clouds
magellanic clouds, a popular name for the two nebiculae, or cloudy-looking areas in the southern sky, which comprise a great number of small stars much resembling the Milky Way. They were named after Ferdinand Magellan.
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"magellanic clouds." The Oxford Companion to Ships and the Sea. 2006. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "magellanic clouds." The Oxford Companion to Ships and the Sea. 2006. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O225-magellanicclouds.html "magellanic clouds." The Oxford Companion to Ships and the Sea. 2006. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O225-magellanicclouds.html |
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