Gamma-ray bursts (GRBs), the universe’s most energetic explosions marking the end of a star’s life, reached a new milestone with GRB 221009A. Detected on October 9, 2022, by several space telescopes, including ESA’s INTEGRAL and NASA’s Swift, this burst emitted an astounding 1,000 times more energy than the Sun has generated during its entire 4.5 billion-year lifetime. Lasting just five minutes, GRB 221009A is now recognized as the most energetic gamma-ray burst ever recorded. Scientists, led by astronomer Daniele Bjørn Malesani, utilized the Very Large Telescope (VLT) in Chile to determine that the event originated more than two billion light-years away, a relatively close distance in astronomical terms.
Despite extensive observations, including with the James Webb Space Telescope, researchers found no convincing evidence of an accompanying supernova, a common expectation during such bursts. This unexpected outcome raises questions about the nature of gamma-ray bursts and their origins. The transient nature of these events and their detection challenges—gamma rays being absorbed by Earth’s atmosphere—complicated previous studies, making GRB 221009A even more remarkable in its implications for astrophysics and our understanding of the cosmos.
