Spiral galaxy M101, LRGB colour stack May 28th, 2012 at Ebenwaldhöhe, Lower Austria GSO 254mm f/5 Newton ATIK 383L+ CCD Kamera Total exposure time approx. 1.5h LRGB composit from 80% of best frames (L 2160s, R 1440s, G 960s, B 960s)