These "quasi-stellar radio sources" are among the brightest & most distant objects in the universe
Although the true nature of these 
objects was controversial until the early 1980s, there is now a ... and are among 
the most luminous, powerful, and energetic objects known in the universe, 
emitting up to a... [DOC] [TLE] Quasars: Definition & Facts About Brightest Objects in the Universe [PAR] Aug 23, 2012 ...