ASN member Jeff Wolff created this beautiful photo of the spiral galaxy M101 on June 3rd with his new ASI1600MC-cool, a color 16 megapixel camera with set-point cooling. The cooler was set to -20 degrees C. The camera was attached to his 10 inch f4 newtonian scope with a ParaCorr II coma corrector in his home observatory (SW Reno!). The image is a stack of thirteen 60-second exposures, which greatly reduces the effects of ambient artificial light. No light-pollution filter was used.
M101 is 27 million light years away, about half the distance of the Virgo Cluster. It is about twice the diameter of the Milky Way and is thus among the largest spiral galaxies. M101 can be found just above the Big Dipper's handle and has a visual magnitude of +7.9.