Originally discovered by radio astronomers, Cas A derives its name from the fact that it was the first radio-wave-emitting object to be discovered in the constellation Cassiopeia. Aside from the Sun, Cas A is the strongest astronomical source of radio waves. This image uses false color to represent the varying strengths of the radio waves emanating from the nebulaΓÇÖs different parts.
Astronomers believe that the faint blue cloud is a nearly spherical shell, the center of which is in the approximate location of the destroyed star. This shell probably represents where the outer layers of the exploded star, originally hurled into space at enormous speeds, have collided over the centuries with interstellar
