Although the spiral galaxy Cygnus A is 500 million light years away, it is the second strongest radio source in the heavens. This image is a composite of three photographs taken in different wavelengths of light. Because the center of Cygnus A appears in red, low-energy wave- lengths, one might assume the galaxy is relatively cool. But Cygnus A is known to be like our own galaxy and consist of hot stars. It appears cool because intervening dust and gas scatter the shorter wavelengths. Blue areas in the image are those where little material blocks our view; yellow and green areas are obscured to some degree; red represents regions that are heavily occluded. 
    Most of the sources seen in this image are galaxies belonging to a