Cygnus A is the best known of the group of dumbbell galaxies. It consists of two nuclei in a common halo. It could be an extreme case of double galaxies. Galaxies are often radio sources.. Cygnus A is so-called because of the constellation in which it is located.. The galaxies at the center of radio star Cygnus A are photographed with the 200-inch telescope. These galaxies are practically at the limit of present optical observation. However, they are one of the strongest radio sources in the sky. Minkowski interprets Cygnus A as two galaxies, of about 100 billion stars each, in head-on collision – a catastrophe of tremendous magnitude. A different interpretation is that these two galaxies are the fragments of one original galaxy undergoing fission, that is, blowing apart in an explosion that must be just as violent as Minkowski’s …