Here’s a long exposure photograph of the spiral galaxy Messier 100. I collected the data for this picture over several nights in late February this year. Exposure times were 2 hours each of Red, Green and Blue color channels and 2 hours 40 minutes of Luminance. Total exposure time: 8 hours and 40 minutes.
Click the image above for a larger picture, or download this high res version of m100 3630×2420.
Located roughly 55 million light years from Earth, Messier 100 is a grand design spiral galaxy estimated to be 160,000 light years wide.