Quasars, some of the rarest objects in the universe, are extremely luminous sources of electromagnetic energy found at the center of galaxies. Mysterious sources of energy for decades, the scientific consensus is that a quasar is a compact region of a massive galaxy that surrounds a supermassive black hole. Quasars have luminosities more than 100 times greater than the Milky Way, and get their energy from the mass in the accretion disk of the black hole. When quasars were first observed, they appeared as point sources of energy, just like stars. However, these quasi-stellar objects were found to emit radiation almost uniformly across the electromagnetic spectrum.

The energy emitted by a quasar must come from beyond the event horizon of the black hole, since no light can escape from inside the black hole. As material falls into the black hole, it experiences extreme gravitational stress. The resulting friction is what powers the intense luminosity of the quasar. Using the Sloan Digital Sky Survey, researchers have observed more than 500,000 quasars, some up to 29 billion light years away.

Given their rarity, the probability of finding multiple quasars in proximity is very low. There have only been about a hundred binary quasars, and two triple quasar systems discovered. Last year, researchers from the Max Planck Institute for Astronomy in Germany detected the first quadruple quasar, with all four being located within 700,000 light years away from each other.

"The … probability of that occurring is extremely small — about 1 in 10 million odds."

- Joesph Hennawi, Max Planck Institute

The group was studing 29 quasars in search of a Lyman-alpha nebulae. When they focused the Keck telescope onto the nebula, they identified the four quasars in close proximity – a true ‘Jackpot Nebula,’ as it’s now known. According to Hennawi, since the quadruple quasar was found in a giant cool nebulae, this might be related to the discovery. The next step for researchers would be to identify how these multi-quasar systems can be generated.