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Large Magellanic Cloud

The Large Magellanic Cloud (LMC) is a satellite galaxy of the Milky Way. At a distance of about 50 kiloparsecs (≈163,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (~16 kpc) and the possible dwarf irregular galaxy known as the Canis Major Overdensity. Based on readily visible stars and a mass of approximately 10 billion solar masses, the diameter of the LMC is about 14,000 light-years (4.3 kpc), making it roughly one one-hundredth as massive as the Milky Way. This makes the LMC the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33). The Large Magellanic Cloud (LMC) is a satellite galaxy of the Milky Way. At a distance of about 50 kiloparsecs (≈163,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (~16 kpc) and the possible dwarf irregular galaxy known as the Canis Major Overdensity. Based on readily visible stars and a mass of approximately 10 billion solar masses, the diameter of the LMC is about 14,000 light-years (4.3 kpc), making it roughly one one-hundredth as massive as the Milky Way. This makes the LMC the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33). The LMC is classified as a Magellanic spiral. It contains a stellar bar that is geometrically off-center, suggesting that it was a barred dwarf spiral galaxy before its spiral arms were disrupted, likely by tidal interactions from the Small Magellanic Cloud (SMC), and the Milky Way's gravity. With a declination of about -70°, the LMC is visible as a faint 'cloud' only in the southern celestial hemisphere and from latitudes south of 20° N, straddling the border between the constellations of Dorado and Mensa, and appears longer than 20 times the Moon's diameter (about 10° across) from dark sites away from light pollution. The Milky Way and the LMC are expected to collide in approximately 2.4 billion years. Although both clouds have been easily visible for southern nighttime observers well back into prehistory, the first known written mention of the Large Magellanic Cloud was by the Persian astronomer 'Abd al-Rahman al-Sufi Shirazi (later known in Europe as 'Azophi'), in his Book of Fixed Stars around 964 AD. The next recorded observation was in 1503–4 by Amerigo Vespucci in a letter about his third voyage. In this letter he mentions 'three Canopes , two bright and one obscure'; 'bright' refers to the two Magellanic Clouds, and 'obscure' refers to the Coalsack. Ferdinand Magellan sighted the LMC on his voyage in 1519, and his writings brought the LMC into common Western knowledge. The galaxy now bears his name. Measurements with the Hubble Space Telescope, announced in 2006, suggest the Large and Small Magellanic Clouds may be moving too fast to be orbiting the Milky Way. The Large Magellanic Cloud has a prominent central bar and a spiral arm. The central bar seems to be warped so that the east and west ends are nearer the Milky Way than the middle. In 2014, measurements from the Hubble Space Telescope made it possible to determine that the LMC has a rotation period of 250 million years.

[ "Galaxy", "Stars", "Classical Cepheid variable", "Hodge 301" ]
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