The Triangulum Galaxy is a member of our local group of galaxies, at a distance of about 3 million light years from earth. It is a spiral galaxy that we observe nearly face-on. The Triangulum Galaxy is sometimes called the Pinwheel Galaxy, but this name is correctly reserved for another galaxy, M101.
M33 was discovered by Charles Messier in 1764 and became the 33rd member of his famous catalog of celestial objects. Although Messier had no knowledge of it, this galaxy had been previously discovered, before 1654, by Giovanni Hodierna.
This photo is a composite of thirty 3 minute exposures made on the night of 30-Oct-2008 with a Canon Digital Rebel XT at the prime focus of a 200mm f/4.9 newtonian reflector telescope. The raw frames were calibrated, registered and stacked with Iris software and final adjustments were made in Photoshop. The telescope was mounted on an Orion Atlas equatorial mount and the mount was controlled with EQMOD software and guided with PHD Guiding software. The guiding camera was a Meade DSI-C, mounted on an 80mm f/11 refractor telescope.