M31 is a spiral galaxy located about 2.5 million light-years from Earth, and is the largest major galaxy to Earth. In 1923, the galaxy was proven by Edwin Hubble to indeed be a separate galaxy from the Milky Way (at the time it was believed the Milky Way contained everything in the universe). The galaxy is bright at mag. 3.4, and is also very large at 3×1 degrees. The barred spiral galaxy is on a collision course with the Milky Way, which, in 4-5 billion years, will result in a head-on collision resulting in a completely new elliptical galaxy nicknamed Milkomeda.
The galaxy is the farthest object visible to the naked eye from Earth and has two satellite galaxies, Messier 32 (up and left) and Messier 110 (down and right). A giant arc-like nebula of oxygen gas was recently discovered by backyard astrophotographers near M31 (more specifically near M32), but since the nebula is extremely faint, it didn’t show up in my photo. Maybe in the future I’ll catch it!
