M33 in Triangulum.

M33 in Triangulum. This galaxy is commonly named the pinwheel galaxy, it lies in the constellation of Triangulum at a distance of about three million light years. This image was taken using my ten inch F4.8 reflector, PHD auto guiding and an Atik 383L mono CCD camera.The sky conditions were very good on this particular evening with only light pollution to contend with. I captured five minute sub frames with matching dark frames and combined them with flat field frames to reduce the effect of vignetting in the final image. The total exposure times were 30 minutes using a red filter, 30 minutes using a green filter, 40 minutes using a blue filter and 40 minutes using a H-Alpha filter: