Monday, 29 September 2008

Our overlooked galactic neighbour

M33, or the Pinwheel galaxy is only slightly further away than the Great Andromeda galaxy (2½ million light years!), but it can only just be seen with the naked eye from a very dark site, on a good night. I got this shot yesterday at the equinox sky camp in North Norfolk through the 400mm telephoto lens, and pushed the contrast a lot. It has a very low surface brightness as it is almost face-on to us, which makes it difficult to see well. I need more exposure time with this one, but I will have to sort out my scope's tracking motor and find some very dark skies to some good shots.


Got this shot by stacking a few 0.5 and 0.8 second exposures with the Canon at the end of a barlow, slid out from it's regular position to increase magnification - a 4,500 mm zoom lens if you like. The width of the disk from the image works out to be a very tiny 3.5" (arc seconds), close to the actual value of 3.7". I boosted the contrast but the colour is natural. It is a good example of what you can get from a back yard in the middle of a city!