New information has been found regarding an extremely powerful and long-lasting cosmic explosion, causing scientists to generate new theories about how stars die.
A research team led by the University of Warwick found examples of the unusual explosions, which create powerful emissions of high energy gamma rays called gamma-ray bursts. While most gamma-ray bursts last less than one minute, these explosions can continue for several hours.
The first instance of the mysterious, massive explosion was detected on Christmas Day 2010, but scientists at that time were unable to measure how far away the explosion took place. The new research suggests that the explosion occurred in a galaxy much farther away than was previously believed. Using the Gemini Observatory telescope in Hawaii, the scientists found that the explosion occurred around halfway between Earth and the edge of the observable universe, about seven billion light-years away.
The scientists now theorize that the massive explosion was caused by a supergiant. Supergiants are stars 20 times as large as the sun that evolve to a radius of up to one billion miles.
"These events are amongst the biggest explosions in nature, yet we're only just beginning to find them," team lead Dr. Andrew Levan of the University of Warwick said. "It really shows us that the universe is a much more violent and varied place than we'd imagined. Previously we've found lots of gamma-ray events with short durations, but in the past couple of years we've started to see the full picture."
According to second author of the study and professor at the University of Leicester Nial Tanvir, the team theorizes that the explosions could be deriving their power from newly formed black holes at the stars' cores.
"Predicting the detailed behavior of matter falling into a black hole in these circumstances turns out to be very difficult, and from a theoretical point of view we didn't initially expect explosions at all," Tanvir said in a statement. "The amazing thing is that nature seems to have found ways of blowing up a wide range of stars in the most dramatic and violent way."
