|Galaxy NGC 6946 and Open Cluster NGC 6939
Order emerges from chaos in this image of two echelons of celestial structure. Although both the Galaxy NGC6946 and the Open Cluster NGC 6939 appear balanced in size within the constellation Cepheus, the Galaxy is
over a thousand times farther away at a distance of 18 million light years. Thus the galaxy, with the light equal to 30 billion suns, dwarfs the cluster in absolute dimensions. Nonetheless, small telescopes showcase the
open cluster, a relative neighbor within our own Milky Way Galaxy, whereas the much fainter Galaxy NGC6946 requires a large telescope for visual observation.
The image "close-up" above combined 3.5 hours through RGB filters (R88, G112, B96), and a synthetic luminance, using a QSI-583wsg camera through a Astro-Physics Ricardi Honders 305 mm astrograph at f3.8.
The image below combined 6 hours through RGB filters (R150, G100, B110), with the sharpest 3 hours used to create a sharper synthetic luminance, using a QSI-583wsg camera through a TEC 140 mm refractor at f7.
The image at the bottom was obtained in 2003, and is an LRGB composite of 99:24:21:27 minutes exposure, for a total imaging time of 3 hours using an ST-10XME CCD camera through a 4" refractor.
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