Brightest light ever observed

The brightest and most energetic event ever recorded by astronomers was a gamma-ray burst GRB221009A, which was recorded on October 9, 2022. Nicknamed the “BOAT” (Brightest Of All Time), satellite-mounted instruments recorded a peak of 6.5 million gamma ray photons per second coming from the distant object, each carrying an energy of 18 teraelectronvolts – or around two times the power than the Large Hadron Collider can impart on particles.

The BOAT lasted approximately seven minutes and contained more energy than if the entire sun’s mass was converted into energy at once. It slightly disturbed the Earth’s ionosphere, despite being unimaginably distant at 2.4 billion light years from Earth. The BOAT's true brightness is not fully measured because it saturated the detectors of almost all gamma-ray instruments in space. Astronomers believe gamma-ray bursts like this are caused by a supermassive star explodes into a supernova at the end of its life.

The previous holder of this record was GRB130427A, first observed on 27 April 2013, which was less than a tenth of the power of the BOAT. The history of gamma ray burst astronomy dates back to the late 1960s, when satellites designed to monitor Earth for signs of undisclosed nuclear weapons tests started picking up unexpected surges of gamma radiation from deep space.