A recent observational campaign involving more than two dozen optical telescopes and NASA's space based SWIFT X-ray telescope allowed a team of astronomers to measure very accurately the rotational rate of one of the most massive black holes in the universe. The rotational rate of this massive black gap is one third of the maximum spin rate allowed in General Relativity. This 18 billion solar mass heavy black gap powers a quasar called OJ287 which lies about 3.5 billion light years absent from soil. Quasi-stellar radio sources or `quasars' for short, are the very bright centers of distant galaxies which emit enormous amounts of electro-magnetic radiation due to the infall of matter into their massive black holes.
Source: phys.org