Andromeda Galaxy

The Andromeda Galaxy (/ænˈdrɒmɨdə/) is a spiral galaxy approximately 2.5 million light-years (2.4×1019 km) from Earth in the Andromeda constellation. Also known as Messier 31, M31, or NGC 224, it is often referred to as the Great Andromeda Nebula in older texts. The Andromeda Galaxy is the nearest spiral galaxy to our Milky Way galaxy, but not the closest galaxy overall. It gets its name from the area of the sky in which it appears, the constellation of Andromeda, which was named after the mythological princess Andromeda. The Andromeda Galaxy is the largest galaxy of the Local Group, which also contains the Milky Way, the Triangulum Galaxy, and about 30 other smaller galaxies. Although the largest, the Andromeda Galaxy may not be the most massive, as recent findings suggest that the Milky Way contains more dark matter and could be the most massive in the grouping. The 2006 observations by the Spitzer Space Telescope revealed that M31 contains one trillion (1012) stars: at least twice the number of stars in the Milky Way galaxy, which is estimated to be 200–400 billion.

The Andromeda Galaxy is estimated to be 7.1×1011 solar masses. In comparison a 2009 study estimated that the Milky Way and M31 are about equal in mass, while a 2006 study put the mass of the Milky Way at ~80% of the mass of the Andromeda Galaxy. The two galaxies are expected to collide in 3.75 billion years, eventually merging to form a giant elliptical galaxy.

At an apparent magnitude of 3.4, the Andromeda Galaxy is notable for being one of the brightest Messier objects, making it visible to the naked eye on moonless nights even when viewed from areas with moderate light pollution. Although it appears more than six times as wide as the full Moon when photographed through a larger telescope, only the brighter central region is visible to the naked eye or when viewed using binoculars or a small telescope.

Read more about Andromeda Galaxy:  Observation History, General, Structure, Nucleus, Discrete Sources, Satellites, Future Collision With The Milky Way

Other articles related to "andromeda galaxy, andromeda, galaxy":

Andromeda Galaxy - Future Collision With The Milky Way
... The Andromeda Galaxy is approaching the Milky Way at about 100 to 140 kilometres per second (62 to 87 mi/s) (400 lightyears every million years), making it one of the few blueshifted galaxies ... The Andromeda Galaxy and the Milky Way are thus expected to collide in about 4.5 billion years, although the details are uncertain since Andromeda's tangential velocity with respect to the Milky Way is known to ... the galaxies will merge to form a giant elliptical galaxy ...
Star Trek: Odyssey - Episode Listing
... undertakes a daring mission to stop ruthless invaders from the distant Andromeda Galaxy ... Mysterious ships from the Andromeda Galaxy have begun an invasion, and seem all but completely unstoppable ... ODY1.05 - 11/26/08 "Keepers of the Wind" Odyssey has struggled in the Andromeda Galaxy for a year ...
Future Of An Expanding Universe - Timeline - Stelliferous Era - Milky Way Galaxy and The Andromeda Galaxy Merge Into One
17 billion years after the Big Bang) The Andromeda Galaxy is currently approximately 2.5 million light years away from our galaxy, the Milky Way Galaxy, and the galaxies ... from now, or 17 billion years after the Big Bang, the Milky Way and the Andromeda Galaxy may collide with one another and merge into one large galaxy ... Because it is not known precisely how fast the Andromeda Galaxy is moving transverse to us, it is not certain that the collision will happen ...
Galaxies In Fiction - Andromeda Galaxy - Music
... The Andromeda galaxy has also featured heavily in the central theme of Enigma's sixth album A Posteriori, in which a collision involving the Milky Way is prophesied to occur in the distant future ...
Interstellar Concordium - Other Galaxies - Andromeda Galaxy
... Universe… Andromedan Invaders The Andromedans (who were backtracked to a galaxy visible in the Andromeda constellation from Earth) were first contacted in the Alpha Octant ...

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