Target: M31 - Andromeda Galaxy
Telescope: Vixen ED80Sf
Camera: Canon 40D (modified, cooled)
Filter: IDAS LPS
Exposures: 96x240s (6.4h) @ ISO1600
Framing: North is Left, Full Frame,
Center (RA, Dec): (10.735, 41.270)
Radius: 1.561 deg
Location: Mocksville, NC
Ambient Temp: 32F
Start Time: 9:00PM
End Time: 4:00AM
Captured with BackyardEOS, stacked using DeepSkyStacker, processed in Photoshop.
The Andromeda Galaxy
) is a spiral galaxy
approximately 2.5 million light-years from Earth
in the constellation Andromeda
. It is also known as Messier 31
, or NGC 224
, and is often referred to as the Great Andromeda Nebula
in older texts. Andromeda is the nearest spiral galaxy to the Milky Way
, but not the closest galaxy
overall. It gets its name from the area of the sky in which it appears, the Andromeda constellation, which was named after the mythological princess Andromeda
. Andromeda is the largest galaxy
of the Local Group
, which consists of the Andromeda Galaxy, the Milky Way, 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)
: at least twice more than the number of stars in our own galaxy, which is estimated to be c. 200–400 billion.
Andromeda is estimated to be 7.1×1011 solar masses
In comparison a 2009 study estimated that the Milky Way and Andromeda are about equal in mass,
while a 2006 study put the mass of the Milky Way at ~80% of the mass of Andromeda. The Andromeda Galaxy and the Milky Way are expected to collide
in perhaps 4.5 billion years.
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 a binoculars
or a small telescope.