Answer: Quasars
Notes: Quasars are extremely luminous cores of distant galaxies that are powered by supermassive black holes. Recently, a group of astronomers have discovered a dozen quasars, distorted by a cosmic lens and split int four similar images. The first such quadruple image was discovered in 1985. The study by “Gaia Gravitational Lenses Working Group” of astronomers, also included scientists from ARIES, Nainital.
