| M31 is the closest spiral galaxy to our own Milky Way. Located 2.3 million light years away one can easily find this in the Andromeda constellation with their naked eye on clear moonless nights. Historically speaking this galaxy is first mentioned by the Persian astronomer Al Sufi in the year 905 A.D. and can be found on star charts dating back before the invention of the telescope. On clear moonless nights away from city lights and with a pair of quality binoculars this object can be traced out to an angular size of 4 degrees. To give you a comparison the full moon has an angular size of just 1/2 a degree. NOAO has
a nice image to demonstrate this angular scale.
|L R G B color production was used to create this image.||
Minimum credit line: Adam Block/NOAO/AURA/NSF
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