The most luminous quasar (quasi stellar radio sources) currently known is reported in the latest version of Nature.
At the "borders" of the universe, 12.8 billion light years from earth, only 900 million years after the big bang this Quaser was formed. The massive black hole has a mass of 12 billion solar mass. It's not the most massive one (cfr 39 billion solar mass) but in comparison with the black hole in our milky way of 4.1 million solar mass, it's gigantic.
