AT2021lwx: The Brightest Cosmic Explosion and Its Implications

This illustration portrays a galaxy with a brilliant quasar positioned at its core. A quasar is an extremely bright, distant, and energetic supermassive black hole that is millions to billions of times larger than the Sun. It is one of the brightest objects in the universe, and its light outshines the light emitted by all the stars in its host galaxy combined. Quasars consume infalling matter and release a flurry of winds and radiation, influencing the galaxies in which they reside. Using the unique capabilities of the Webb telescope, scientists intend to investigate six of the most remote and radiant quasars in existence. Credit: J. Olmsted (STScI), NASA, and ESA

May 14, 2023

AT2021lwx is a cosmic explosion that has recently captured the attention of the astrophysics community. It is the largest cosmic explosion ever observed, and it is ten times brighter than any known exploding star or supernova. The explosion was detected by telescopes nearly 8 billion light-years away from Earth when the universe was about 6 billion years old, making it an extremely significant event in the history of the cosmos.

The event was detected in November 2020 by the Zwicky Transient Facility in California, followed by the Asteroid Terrestrial-impact Last Alert System in Hawaii a few months later. Both facilities observe objects in the night sky that rapidly change in brightness, such as exploding stars, asteroids, and comets.

The explosion, named AT2021lwx, has been described by astronomers as a super-luminous supernova, meaning that it was exceptionally bright and long-lasting. Unlike most supernovas, which are only bright for a few months, AT2021lwx has remained bright for over three years.

Astronomers have suggested that a supermassive black hole disrupted a vast gas or dust cloud, which could be thousands of times larger than our sun, leading to the explosion. As the black hole swallowed pieces of the hydrogen cloud, shock waves likely reverberated through the cloud’s remnants and into the swirling mass of material that orbits around the black hole.

The brightness of the explosion is also three times brighter than tidal disruption events when stars fall into supermassive black holes. This makes AT2021lwx the brightest recorded cosmic explosion, dethroning gamma-ray burst GRB 221009A, which was reported in 2022. The gamma-ray burst was actually brighter, but it only lasted for a fraction of the duration of AT2021lwx, which is releasing more energy overall.

AT2021lwx is nearly 100 times brighter than all the 100 billion stars in the Milky Way galaxy combined. The only celestial objects to rival the brightness of AT2021lwx are quasars, or supermassive black holes that constantly feed on gas at a high velocity.

The discovery of AT2021lwx is significant for astrophysics as it provides new insights into the behavior of black holes and the phenomena that surround them. It also sheds light on the processes that lead to the formation of galaxies, as supermassive black holes are thought to play a critical role in the evolution of galaxies.

The research team is now collecting more data across different wavelengths of light to learn about the details of the event, including its temperature. This information could provide important clues about the processes that occur in the vicinity of supermassive black holes, which are some of the most mysterious and fascinating objects in the universe.

The findings have been published in the Monthly Notices of the Royal Astronomical Society, and they represent a significant breakthrough in our understanding of the cosmos and the processes that drive its evolution. The discovery of AT2021lwx is a testament to the incredible advances that have been made in astronomical observation and the immense potential of these tools to unlock the secrets of the universe.