Is Andromeda galaxy the biggest galaxy?

Answer 1

Although the Andromeda Galaxy is a bit larger than the Milky Way, and is large as spiral galaxies go, it is not the largest galaxy. There are larger spiral galaxies, and much, MUCH larger elliptical galaxies. However, because it is relatively close to the Milky Way, the Andromeda Galaxy _appears_ quite large, spanning an apparent width roughly six times that of a full Moon. Still, there are two smaller, closer galaxies (the Magellanic Clouds) which appear larger still. (The Magellanic Clouds are not visible from northern latitudes, however, so one could argue that the Andromeda Galaxy is the biggest galaxy in _apparent size_ visible from most of the northern hemisphere.)