The Andromeda Galaxy
M31, M32 and M110
The Andromeda Galaxy (M31, or NGC 224) is the closest spiral galaxy to the Milky Way Galaxy, located approximately 2,500,000 light years from the Alpha Quadrant at its closest point.
A picture of the Andromeda Galaxy was on display in the briefing room of the USS Enterprise when the crew was reviewing star charts to search for the origin of an unknown buoy. (TOS: "The Corbomite Maneuver")
An ancient humanoid race from the Andromeda Galaxy became extinct following the destruction of their homeworld when their sun went supernova. Remnants of the species survived for a time on scattered outposts but eventually died out, leaving their android populations on their own. One of these android-populated outposts was the planet Mudd in the Milky Way Galaxy. (TOS: "I, Mudd")
Centuries ago, Kelvans became aware of dangerously rising radiation levels in Andromeda, a development expected to make that galaxy uninhabitable for their species within 10,000 years. The Kelvan Empire has dispatched expeditions of multi-generational starships to explore the neighboring galaxies for territories suitable for conquest and occupation. (TOS: "By Any Other Name")
Hypothetically, a Constitution-class starship running at maximum warp, would take thousands of years to complete the journey to Andromeda. (TOS: "By Any Other Name")
Apocrypha
- In Star Trek: Odyssey, the upcoming Fan Series made by the people who make Star Trek: Hidden Frontier, is the first Star Trek Series to take place in the Andromeda Galaxy.