Astronomers working with The LHAASO Collaboration have made a groundbreaking discovery concerning last year’s gamma-ray burst, GRB 221009A, affectionately dubbed the Brightest of All Time (BOAT). Their study, recently reported in the journal Science Advances, involved analyzing data from the LHAASO-KM2A detector located in Sichuan, China.
Gamma-ray bursts are known as the brightest explosions observable from Earth, and their origins have been the subject of various theories. Some propose neutron star collisions, while others suggest mergers between neutron stars and black holes or the collapse of massive stars into black holes.
GRB 221009A, detected on October 9, 2022, by the Gemini South telescope in Chile, stood out due to its unprecedented energy levels—carrying a staggering 13 teraelectronvolts. Prior research indicated that gamma-ray bursts typically registered around half a teraelectronvolt or less before this discovery. Situated approximately 2.4 billion light years away, GRB 221009A lasted a remarkable 70 times longer than any previously recorded gamma-ray burst, marking it as a rare 1 in 10,000-year event.
The LHAASO Collaboration has spent the past year closely studying BOAT, uncovering intriguing details about its origin. The star involved was approximately 20 times larger than our sun, and the burst endured for several hundred seconds. Moreover, more than 140 gamma rays in the burst exhibited energies surpassing 3 teraelectronvolts, challenging existing energy level expectations.
Equally perplexing is the observation that the afterglow of the burst persisted longer than current theories predict. This unexpected behavior has prompted the LHAASO Collaboration team to extend their investigation, aiming to unravel the mysteries surrounding the causes and post-burst dynamics of gamma-ray events.
As the scientific community awaits further insights from ongoing research, the extraordinary nature of GRB 221009A continues to captivate astronomers, shedding light on the complexities of these cosmic phenomena.