NGC 6946 is a medium-sized, face-on spiral galaxy about 22 million light years away from Earth. In the past century, eight supernovas have been observed to explode in the arms of this galaxy. Chandra observations (purple) have, in fact, revealed three of the oldest supernovas ever detected in X-rays, giving more credence to its nickname of the "Fireworks Galaxy." This composite image also includes optical data from the Gemini Observatory in red, yellow, and cyan.
Image credit: X-ray: NASA/CXC/MSSL/R.Soria et al, Optical: AURA/Gemini OBs
NASA
<a rel="nofollow" class="external free" href="http://www.nasa.gov/mission_pages/chandra/multimedia/fireworks-galaxy-ngc6946.html#.UteCAtIW1mN">http://www.nasa.gov/mission_pages/chandra/multimedia/fireworks-galaxy-ngc6946.html#.UteCAtIW1mN</a>