Thanks to the gravitational lensing effect, the galaxy cluster Abell 2744 acts as a colossal natural telescope, magnifying and multiplying the image of a very distant quasar--designated QSO1--which we see as it appeared just 700 million years after the Big Bang, when the universe was only 5% of its current age. This lensing effect provides three images of the same quasar, allowing us to determine that it measures approximately 1,300 light-years in diameter and contains a black hole with a mass 50 million times that of the Sun. Those tiny red dots are incredibly faint flickers that enable us to study the most remote past of our universe.
ESA
