NASA’s NuSTAR X-ray telescope has given astronomers a clue as to why GRB 221009A, the brightest and most energetic gamma-ray burst ever detected, is so powerful. On October 9, 2022, scientists observed this unprecedented event and recorded it as 70 times brighter and more energetic than any other gamma-ray burst they had seen before. NuSTAR has revealed that this enormous burst of energy took place when the core of a massive star, much larger than our own sun, collapsed into a black hole. This event released as much energy in a few minutes as our sun would release in its entire lifetime. While scientists are still on the search for a full explanation as to why GRB 221009A produced such an extraordinary display, they are thankful to have obtained this insight from NuSTAR.
In a study recently published in the journal Science Advances, scientists used NuSTAR observations to analyze the event of a collapsing star that ejected a jet of material that was unlike any other gamma-ray burst jets. This unique jet had certain characteristics that could possibly be sourced from the progenitor star, like its physical properties. Moreover, it is also suggested that an entirely different mechanism could be responsible for launching the brightest jets into space.
This event was truly remarkable – it was far brighter and more energetic than any gamma-ray burst ever seen before. Brendan O’Connor, the lead author of the study and an astronomer at George Washington University in Washington, noted that even more interesting was the unique jet structure which was revealed when analyzing the NuSTAR data. This was particularly exciting since there was no way to study the star that produced this event as it has vanished, but now they have some data giving them clues about how it exploded.
Gamma rays are the most energetic form of light in the universe yet invisible to the human eye, emitting radiation from galaxies billions of light-years away. Gamma-ray bursts are among the brightest cosmic events yet, with some lasting for less than two seconds, while others can radiate for up to a minute or more. Not only do they emit gamma-rays, but they can also emit other wavelengths for weeks. All known gamma-ray bursts have originated from galaxies outside our Milky Way and are bright enough to be spotted from far away, making them an important part of astronomical study.
The Hubble Space Telescope captured the infrared aftermath of a known gamma-ray burst.
The Hubble Space Telescope captured the infrared afterglow of the gamma-ray burst known as GRB 221009A and its host galaxy in a composite image taken on November 8 and December 4, 2022, approximately one and two months after the eruption. The afterglow was visible in the image, with the bright circle indicating its location. This afterglow can still be detected from Hubble for several years to come. This data is important as it allows scientists to better understand the origins and behavior of gamma-ray bursts.