GRBs are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from several milliseconds to several hours, producing as much energy as the Sun will emit during its entire existence.

 

The GRBs with a longer duration are generated by the collapse and explosion of stars with dozens of times the mass of the Sun, while the short bursts are produced by the merger of two compact celestial bodies, such as black holes or neutron stars, which may also be accompanied by gravitational waves, scientists say.

 

"GRB 221009A is a long burst, which occurred more than two billion light years away from Earth. A GRB with such huge brightness is estimated to occur only once in decades," said Zhang Shuangnan, director of the Division for Particle Astrophysics of IHEP, as well as the principal investigator of Insight-HXMT.

 

According to Cao Zhen, the principal investigator of LHAASO, in this observation, LHAASO detected a large number of high-energy photons, reaching a maximum photon energy of 18 TeV.

 

"With the combined observations of LHAASO, HEBS and Insight-HXMT, we found that this event was more than 10 times brighter than the brightest gamma-ray burst previously observed by humans," he said.

 

"This observation has broken several records for gamma-ray burst observations and is of great value in revealing the outburst mechanisms of gamma-ray burst," Cao added.