Astronomers report an object that shines with a brightness equivalent to 500 trillion suns.
Science correspondentIt's a quasar - the bright core of a galaxy that is powered by a gargantuan black hole some 17 billion times the mass of our Sun.
"We have discovered an object which has previously not been recognised for what it is; it's been staring into our eyes for many years because it's been glowing at its brightness for longer than humankind has probably existed. But we've now recognised it, not as being one of the many foreground stars in our Milky Way but as a very distant object," Christian Wolf, from the Australian National University , told BBC News.
The scientists involved say the energy emitted makes the quasar over 500 trillion times more luminous than the Sun.