Approximately 245 million lightyears in the direction of the constellation Andromeda, The Andromeda Galaxy (also known as M 31 and NGC 224, formerly the Great Spiral Nebula in Andromeda) is our closest neighboring galaxy of similar size, and is projected to merge with the Milky Way in 4-5 billion years. The Andromeda Galaxy played an important role in The Great Debate concerning the size of the universe and the nature of spiral galaxies – then called spiral nebulae or island universes, depending on your side of the argument. The debate was settled in 1925 after Edwin Hubble measured the distance to Andromeda using Cepheid variable stars, and determined it was far outside the range of the Milky Way.

Captured over two nights using a Fujifilm X-A5 and a GSO 6" F/4 Newtonian mounted on a Celestron AVX, and processed with Siril and GIMP. This image is a stack of 5.5 hours total integration time distributed over 221 exposures at 1000 ISO, and calibrated using 40 biases, flats, and darks.