How far away is the quasar?
Quasar, astronomical object that is very bright for its size and distance from Earth. Another important identifying feature of quasars is a shift in the light emitted by quasars that indicates they are moving away from Earth very quickly. Quasars occur at the centers of distant galaxies. Many astronomers believe that quasars are associated with giant black holes at the centers of these galaxies. Black holes are regions of space that are so massive and dense that not even light can escape their gravitational pull. The matter that swirls around black holes releases enormous amounts of energy, which astronomers believe provides quasars’ light. The name quasar is an acronym for quasi-stellar radio source, because quasars appear to be starlike, or pointlike objects in the sky, since they are so far away from Earth. Also, the first quasars observed (in the 1950s) were all strong emitters of radio waves. By the end of the 1990s, only about 10 percent of the total number of quasars discovered
