Telescope: Vixen ED80Sf
Camera: Canon 40D (modified)
Exposures: 52x240 seconds @ ISO1600, 20 Darks
Location: Mocksville, NC
Captured in Nebulosity, stacked using DeepSkyStacker, processed in Photoshop.
The Andromeda Galaxy
, also known as Messier 31
, or NGC 224
; often referred to as the Great Andromeda Nebula
in older texts) is a spiral galaxy
approximately 2,500,000 light-years
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
(Greek: Ανδρομέδη – Andromédē) 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. Although the largest, Andromeda may not be the most massive, as recent findings suggest that the Milky Way contains more dark matter
and may be the most massive in the grouping.
The 2006 observations by the Spitzer Space Telescope
revealed that M31 contains one trillion (1012)
more than twice the number of stars in our own galaxy which is estimated to be c. 200-400 billion.
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
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.