Ed Bianchina's Astronomy

Astrophotography

Galaxies

Andromeda Galaxy

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Andromeda Galaxy
The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda. It is the nearest spiral galaxy to our own, the Milky Way. As it is visible as a faint smudge on a moonless night, it is one of the farthest objects visible to the naked eye, and can be seen even from urban areas with binoculars. It is named after the princess Andromeda in Greek mythology. Andromeda is the largest galaxy of the Local Group, which consists of the Andromeda Galaxy, the Milky Way Galaxy, the Triangulum Galaxy, and about 30 other smaller galaxies. The 2006 observations by the Spitzer Space Telescope revealed that M31 contains one trillion (1012) stars, greatly exceeding the number of stars in our own galaxy. While the 2006 estimates put the mass of the Milky Way to be ~80% of the mass of Andromeda, which is estimated to be 7.1 × 1011 solar masses, a 2009 study concluded that Andromeda and the Milky Way are about equal in mass. At an apparent magnitude of 4.4, the Andromeda Galaxy is notable for being one of the brightest Messier objects,[10] making it easily visible to the naked eye 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 with the naked eye. Combination 140 x 3 min images QHY8 Camera Willams Optics Megrez 80 Telescope @ f/5.4 Atlas mount ST 80 Guide scope/DSI/PHD guilding
Posted on August 26, 2009 Full Size| Slideshow