M33, aka the Triangulum Galaxy, aka NGC 598, is a prominent member of the Local Group of galaxies. This galaxy is small compared to its big apparent neighbor, the Andromeda Galaxy (M31), and to our Milky Way Galaxy, but about average size for spiral galaxies in the universe.
Imaged from New Mexico Skies in 2007 using a 16″ RCOS at f/8.7 with an SBIG STL11K on a Paramount ME. Image scale 0.53″/pixel. This was acquired as a 4 frame mosaic using about 3 hours of Lum/frame and 3 hours of RGB/channel/frame, plus 8 hours Ha data.