OTHER GALAXIES
Messier 31 (NGC 224) The Great Andromeda Galaxy and satellites M 110 & M 32 Constellation: Andromeda Magnitude: 3.4 Distance: 2.5 million light years
The Great Andromeda Galaxy, Messier 31, is the nearest spiral galaxy to our own. Visible as a faint smudge on moonless nights, it is one of the most distant objects visible to the naked eye. Although it is larger than the Milky Way, the structure of Andromeda is very similar to our own Milky Way galaxy which allows us to study the features of our own galaxy that we can’t observe because we’re inside it. The galaxy has a magnitude of 3.4 and is one of the brightest Messier objects. Although the apparent size of the galaxy is about 3 degrees x 1 degree, (six times the size of the full moon!) only the bright central core is visible to the naked eye or binoculars.
Like the Milky Way, Andromeda has smaller, satellite galaxies: M 110 and M 32. M 110 is the galaxy to the upper left of Andromeda in the image. M 32 is the smaller one just to the right of the core of Andromeda. The Andromeda galaxy is approaching the Milky Way at about 100 km/sec (about 62 miles/sec). It is expected to collide with our own galaxy - but not for another 2.5 billion years! It is estimated that Andromeda Galaxy has at least 1 trillion stars - several times the number in our own galaxy, which contains around 500 billion stars. This image was taken with a Canon T5i camera through an AT65ED Quadruplet telescope on the EQ8 mount. Exposure time: 1.7 hours. Technical/capture details are here.