Centaurus A or NGC 5128 is a galaxy in the constellation of Centaurus. It's is located 10-16 million light yeas away. Is one of the closest radio galaxies to Earth and is the fifth-brightest in the sky. The center of the galaxy contains a supermassive black hole with a mass of 55 million solar masses, which ejects a relativistic jet that is responsible for emissions in the X-ray and radio wavelengths. By taking radio observations of the jet separated by a decade, astronomers have determined that the inner parts of the jet are moving at about half of the speed of light.