The English astronomer Sir John Herschel, observing Centaurus A in the nineteenth century, wrote that it was “a most wonderful object . . . cut asunder . . . by a broad obscure band.” Even though Centaurus A’s dust lane hides much of its light, it is still one of the brightest galaxies that we can observe. No wonder it impressed Herschel.
Centaurus A is actually known by two astronomical names. Optical astronomers dubbed this giant elliptical galaxy NGC 5128. Years later, radio astronomers found a powerful radio source near the same site and, not realizing that it was the same object, called the radio galaxy Centaurus A.
Astronomical objects are often named for their location in the sky. Centaurus A is near the southern
