ESA Hubble Science Release | 2019 Jan 09
Quasars are the extremely bright nuclei of active galaxies. The powerful glow of a quasar is created by a supermassive black hole which is surrounded by an accretion disc. Gas falling toward the black hole releases incredible amounts of energy, which can be observed over all wavelengths.
The newly discovered quasar, catalogued as J043947.08+163415.7 , is no exception to this; its brightness is equivalent to about 600 trillion Suns and the supermassive black hole powering it is several hundred million times as massive as our Sun.  ...
Despite its brightness Hubble was able to spot it only because its appearance was strongly affected by strong gravitational lensing. A dim galaxy is located right between the quasar and Earth, bending the light from the quasar and making it appear three times as large and 50 times as bright as it would be without the effect of gravitational lensing. Even still, the lens and the lensed quasar are extremely compact and unresolved in images from optical ground-based telescopes. Only Hubble’s sharp vision allowed it to resolve the system.
The data show not only that the supermassive black hole is accreting matter at an extremely high rate but also that the quasar may be producing up to 10 000 stars per year . ...
Hubble Helps Uncover the Brightest Quasar in the Early Universe
NASA | STScI | HubbleSite | 2019 Jan 09
Astronomers Uncover the Brightest Quasar in the Early Universe
W. M. Keck Observatory | 2019 Jan 09
Cosmic Telescope Zooms in on the Beginning of Time
Gemini Observatory | 2019 Jan 09
The Discovery of a Gravitationally Lensed Quasar at z = 6.51 ~ Xiaohui Fan et al