Caldwell 12 (NGC 6946) Fireworks Galaxy

This galaxy is just outside our local group of galaxies (10 million ly). It is known as the Fireworks Galaxy because more supernovas have been discovered in this galaxy than any other. This is due to a phase of rapid star formation - hence the red emission nebula in the spiral arms. The line of sight to this galaxy goes through our galaxies spiral arm which obscures the galaxy by several magnitudes. If this was not the case it would be one of the brightest galaxies in the sky.

For more information, try: http://www.seds.org/messier/xtra/ngc/n6946.html