M31 - Andromeda Galaxy
The Andromeda Galaxy is the nearest major galaxy to the Milky Way and the largest galaxy in the Local Group. At 2.5 million light-years away, it's the most distant object visible to the naked eye.
Distance: 2.537 million light-years
Apparent Magnitude: 3.44
Apparent Size: 190' × 60' (6x Moon diameter)
Constellation: Andromeda
Morphology: SA(s)b (barred spiral)
Key Features:
- Contains ~1 trillion stars (2.5x Milky Way)
- 14 known dwarf satellite galaxies
- M32 and M110 visible in wide-field images
- Double nucleus discovered by Hubble
- Approaching Milky Way at 110 km/s (collision in 4.5 billion years)
Best Imaging Season: August - February
Optimal Integration: 20+ hours for detail
