Tags: Galaxy.
Cygnus A (3C 405) is one of the most famous radio galaxies and among the strongest radio sources in the sky. It was discovered by Grote Reber in 1939. In 1951 Cygnus A along with Cassiopeia A and Puppis A were the first radio stars identified with an optical source. Of these Cygnus A became the first radio galaxy; the other two being nebulae inside the Milky Way. In 1953 Roger Jennison and M K Das Gupta showed it to be a double source.
