WHAT IS A QUASAR?
A mystery when they were first discovered, we now know these bright objects are powered by supermassive black holes
The first systematic surveys of the sky using radio telescopes turned up hundreds of strong sources, many of which were clearly associated with distant galaxies that could be seen in photographs taken through optical telescopes. But there were a few anomalous sources that didn’t have an obvious galaxy associated with them. After looking very carefully, astronomers spotted that these mysterious sources coincided with what looked like ordinary, point-like stars in optical images. At the time, in the early 1960s, they still had no idea what these objects were, so they gave them the non-committal name of ‘quasi-stellar radio sources’ – soon shortened to ‘quasars’.