NASA's Fermi Telescope Discovers New Phenomenon in Record-Breaking Gamma-Ray Burst

NASA's Fermi Telescope Discovers New Phenomenon in Record-Breaking Gamma-Ray Burst
Image credit: NASA

Record-Breaking Gamma-Ray Burst

NASA's Fermi Gamma-ray Space Telescope has made a groundbreaking discovery by examining what might be the most powerful explosion since the Big Bang. This event, a gamma-ray burst (GRB), was first observed on October 9, 2022, and has been dubbed the Brightest Of All Time (BOAT), designated as GRB 221009A.

Record Breaking Gamma-Ray Burst 
Image credit: Live Science

The Discovery and Initial Observations

On October 9, 2022, high-energy gamma-ray light from the BOAT overwhelmed many of the gamma-ray detectors in orbit, including those on Fermi. This saturation prevented the measurement of the burst's true power at its peak. However, Fermi detected the burst again after it had dimmed, revealing an unusual energy peak. This feature could be the result of matter and antimatter particles annihilating at 99.9% of the speed of light.

Two neutron stars begin to merge in this artist’s concept, blasting jets of high-speed particles. Collision events like this one create short gamma-ray bursts.
Image credit: NASA

Understanding the BOAT's Origins

Scientists theorize that the BOAT was triggered by a supernova explosion following the death and collapse of a massive star located approximately 2.4 billion light-years away. This event likely resulted in the formation of a black hole. GRBs occur when massive stars exhaust their nuclear fuel, causing their cores to collapse and creating jets of matter that travel near the speed of light. When these jets are aimed at Earth, we observe them as GRBs.

As a high-mass star explodes in this artist’s concept, it produces a jet of high-energy particles. We see GRBs when such gets point almost directly at Earth.
Image credit: NASA

Implications and Unique Findings

Researchers found that such a powerful and bright event as the BOAT would only be visible in Earth's sky once every 10,000 years. Despite occurring 2.4 billion light-years away, the BOAT had a measurable impact on Earth's atmosphere. Fermi's observations included a unique "putative emission line" in the light spectra of the BOAT, lasting about 40 seconds and peaking at 12 million electron volts (MeV).

The Role of Matter and Antimatter

The research team believes the spectral feature observed could stem from the annihilation of electrons and positrons (antimatter particles). When these particles collide, they produce gamma rays, significantly blueshifted due to the high velocity of the particles, estimated to be 99.9% of the speed of light.

Historical Context and Future Research

Since the first gamma-ray burst was documented in 1967, scientists have identified many GRBs, recognizing them as the universe's most powerful explosions. The BOAT stands out not only for its brightness but also for the new insights it provides into these cosmic events. The detailed study of the BOAT's features could enhance our understanding of how these jets function.

Publication and Conclusion

The team's research was published on July 26 in the journal Science. Team member Elizabeth Hays from NASA's Goddard Space Flight Center emphasized the significance of these findings, noting that even after decades of study, the details of GRB jets remain elusive, making discoveries like this crucial for advancing our knowledge.