Credit: Yashar Hezaveh, McGill University
South Pole Telescope-discovered galaxy observed by ALMA and Hubble Space Telescope (HST). The massive central galaxy (in blue, seen by HST) bends the light of a more distant, submillimeter-bright galaxy, forming a ring-like image of the background galaxy which is observed by ALMA (red).
Light rays from a distant galaxy are deflected due to the gravity of a massive, foreground galaxy, as predicted by Einstein's theory of general relativity. This makes the background galaxy appear as multiple magnified images surrounding the foreground galaxy.