The red stars and oval shape of Centaurus A are characteristic of a giant elliptical galaxy. Such galaxies are usually poor in gas, dust and young stars, so the presence of young blue stars and large quantities of gas and dust around the center of the galaxy suggests that Centaurus A absorbed a dusty spiral galaxy sometime in the past billion years. The nucleus of Centaurs A harbors a massive black hole whose presence is revealed by uncommonly strong radio emission and X-ray radiation being emitted from the center of the galaxy.

--Space.com staff

credit: Canada-France Hawaii Telescope