There are two types of gamma-ray bursts: short and long. The short GRBs last a very short duration, a maximum of two seconds but sometimes even less. The longer ones are still relatively short, coming in at more than two seconds and sometimes several minutes, with the longest ones typically clocking in between 20 seconds and 50 seconds. A rare type of long GRB has been seen in action a couple times throughout recent years, however, and scientists finally have an answer about what causes them.
Starting in 2010, a new type of gamma ray burst was identified that lasted much longer, followed by two more over the months to 2012. The longest of the three is called GRB 111209A, and is the longest ever noted, having lasted a whopping 7 hours. Such massively long gamma rays have confused astronomers, with the fairly recent phenomenon having only occurred a few times.
This led astronomers to utilize NASA's Swift telescope, a European Space Agency's satellite, and more to study the super gamma ray GRB 111209A, which occurred in late 2011. By doing this, they came to the conclusion that the death of a massive star, which is said to be sized far beyond our sun's mass and forming a black hole, is responsible for the burst.
Bruce Gendre, who led the study, said: "We have observed the longest gamma ray burst in modern history, and think this event is caused by the death of a blue supergiant. It caused the most powerful stellar explosion in recent history, and likely since the Big Bang occurred." The findings were discussed earlier today in Tennessee in a meeting sponsored by the University of Alabama.
[via Science Recorder]