https://wikimd.org/index.php?action=history&feed=atom&title=Andromeda_GalaxyAndromeda Galaxy - Revision history2026-04-25T04:55:14ZRevision history for this page on the wikiMediaWiki 1.44.2https://wikimd.org/index.php?title=Andromeda_Galaxy&diff=5881718&oldid=prevPrab: CSV import2024-06-05T18:41:09Z<p>CSV import</p>
<p><b>New page</b></p><div>[[File:Andromeda_Nebula_-_Isaac_Roberts,_29_December_1888.jpg|thumb|Andromeda_Nebula_-_Isaac_Roberts,_29_December_1888]] [[file:Andromeda_constellation_map.svg|right|thumb|Andromeda_constellation_map]] [[file:Andromeda_Galaxy_560mm_FL.jpg|right|thumb|Andromeda_Galaxy_560mm_FL]] [[file:Milky_Way_and_Andromeda_in_space,_to_scale.jpg|thumb|Milky_Way_and_Andromeda_in_space,_to_scale]] [[file:Hubble_Finds_Giant_Halo_Around_the_Andromeda_Galaxy.jpg|thumb|Hubble_Finds_Giant_Halo_Around_the_Andromeda_Galaxy]] [[file:A_Swift_Tour_of_M31.ogv|thumb|A_Swift_Tour_of_M31.ogv]] [[file:Andromeda_galaxy_Ssc2005-20a1.jpg|thumb|Andromeda_galaxy_Ssc2005-20a1]] {{short description|Spiral galaxy in the constellation Andromeda}}<br />
{{Use dmy dates|date=October 2023}}<br />
{{Infobox galaxy<br />
| name = Andromeda Galaxy<br />
| image = Andromeda Galaxy (with h-alpha).jpg<br />
| image_size = 300<br />
| caption = The Andromeda Galaxy<br />
| epoch = J2000<br />
| type = SA(s)b<br />
| ra = 00h 42m 44.3s<br />
| dec = +41° 16′ 9″<br />
| dist_ly = 2.537 million<br />
| z = -0.001001<br />
| appmag_v = 3.44<br />
| size_v = 3.167° × 1°<br />
| constellation = [[Andromeda (constellation)|Andromeda]]<br />
| notes = Nearest spiral galaxy to the Milky Way<br />
| names = M31, NGC 224, UGC 454, PGC 2557<br />
}}<br />
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The '''Andromeda Galaxy''', also known as '''Messier 31''', '''M31''', or '''NGC 224''', is a [[spiral galaxy]] approximately 2.537 million [[light-years]] from [[Earth]]. It is the nearest spiral galaxy to the [[Milky Way]] and the largest galaxy in the [[Local Group]], which also contains the Milky Way, the [[Triangulum Galaxy]] (M33), and about 54 other smaller galaxies.<br />
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== Discovery and Observation ==<br />
The Andromeda Galaxy is named after the [[Andromeda (constellation)|constellation of Andromeda]], where it appears. It is visible to the naked eye from Earth on clear nights, appearing as a faint, diffuse smudge of light. The galaxy was first cataloged by the Persian astronomer [[Abd al-Rahman al-Sufi]] in 964 AD in his Book of Fixed Stars. It was later observed by [[Simon Marius]] in 1612 and described as a "small cloud."<br />
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== Structure and Composition ==<br />
The Andromeda Galaxy is a barred spiral galaxy with a diameter of about 220,000 light-years, making it the largest galaxy in the Local Group. It contains approximately one trillion stars, more than twice the number of stars in the Milky Way. The galaxy has a prominent central bulge and a well-defined spiral structure with several spiral arms.<br />
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=== Nucleus ===<br />
The nucleus of the Andromeda Galaxy contains a supermassive black hole with a mass estimated to be around 100 million times that of the Sun. The central region is densely packed with stars, and it exhibits significant star formation activity.<br />
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=== Halo ===<br />
The galaxy has a large halo of hot gas and dark matter, extending several hundred thousand light-years from its center. This halo contains numerous globular clusters and satellite galaxies, including [[M32]] and [[M110]].<br />
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== Interaction with the Milky Way ==<br />
The Andromeda Galaxy is on a collision course with the Milky Way, with a predicted merger occurring in about 4.5 billion years. This event will likely result in the formation of a new galaxy, sometimes referred to as "Milkomeda" or "Milkdromeda."<br />
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== Related Pages ==<br />
* [[Milky Way]]<br />
* [[Triangulum Galaxy]]<br />
* [[Local Group]]<br />
* [[Spiral galaxy]]<br />
* [[List of nearest galaxies]]<br />
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== See Also ==<br />
* [[List of Messier objects]]<br />
* [[List of galaxies]]<br />
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== References ==<br />
{{Reflist}}<br />
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{{Galaxies}}<br />
{{Local Group}}<br />
{{Messier objects}}<br />
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[[Category:Andromeda (constellation)]]<br />
[[Category:Local Group]]<br />
[[Category:Spiral galaxies]]<br />
[[Category:Messier objects]]<br />
[[Category:NGC objects]]<br />
[[Category:Astronomical objects known since antiquity]]<br />
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