Gamma Cassiopeiae is the middle star in the constellation Cassiopeia.
The diffraction spikes on this image were introduced by placing a mask over the front of the Edge11. The mask was just some strings pulled across the face then held in place by the dew shield. This was a an experiment to see how much of a diffraction effect a simple bit of string would cause and if it made the images look any better or worse. Artistically, some may say better. Scientifically, probably worse. Personally, I like the spikes, they can make the stars appear to sparkle and can really add to an image if used appropriately.