A very violent explosion, the most powerful that has ever been observed in space: now we know what caused it. But two new mysteries emerge.
Relatively little time has passed since space telescopes spotted one in October 2022 very violent explosion of light: visible in practically all frequencies, however, it was the emission of gamma rays that surprised scientists. Never before had something similar been observed, a phenomenon so powerful that it aroused great curiosity – and many doubts. Today we know what caused this explosion, thus solving a mystery. But Two new puzzles have emerged that are driving astronomers crazy.
The cause of the violent explosion explained
In October 2022, some scientists spotted a very powerful explosion that occurred at approximately 2.4 billion light years away. It was an emission of gamma rays of such intensity that it left experts surprised. The event was renamed GFB 221009A, but is also known by the acronym BOAT (“Brigthest Of All Times”, or “the brightest of all time”). Despite the immense distance, the gamma ray burst it managed to cross space and reach Earth, generating a photon of 18TeV (electron volts) – something truly sensational.
Astronomers have always associated phenomena of this type with two particular events: thehypernova which accompanies the merger of two neutron stars or the birth of a black hole, caused by the violent death of a massive star which causes a supernova. At first, scientists were unable to study what happened in space due to the immense brightness unleashed by the explosion. When this has subsided, the instruments on board the James Webb Space Telescope they were able to peek into what happened. And a surprising detail emerged.
The study conducted byastrophysicist Peter Blanchard from Northwestern University (United States) and his team, published on Nature Astronomy, has in fact revealed that the explosion was caused by a very normal supernova, no brighter than those previously sighted. “One might expect that the same star that collapses producing a very energetic and luminous GRB would also produce one very energetic and bright supernova. But it doesn’t turn out that way” – explained Blanchard, amazed by the results of the analysis. This opens the door to two new mysteries.
The two new mysteries in space
The first enigma concerns the gamma ray burst that reached us: how could it be so powerful, if the supernova that caused it was instead normal intensity? Scientists don’t know, but they hypothesize that it is a bit like the light of a flashlight, which is aimed in a very narrow beam and thus appears much more intense. In this case, the beam would have been pointed straight at Earth – and, indeed, the flash was one of the narrowest jets ever seen for a gamma ray burst. Perhaps this is what caused this brightness.
The second mystery is even more fascinating: scientists have always hypothesized that, when a massive star collapses, produces heavy elements like gold and platinum. However, none of this was found after GFB 221009A. Either the theory is wrong and the heavy elements are produced in some other way, or they are only produced by supernovae that exhibit certain characteristics: “We need to go back to understand why an event like BOAT doesn’t produce heavy elements when theories and simulations predict that it should.” – he concluded Blanchard.
