An international team of astronomers led by the University of Birmingham has identified the biggest and the brightest known supernova. The SN2016aps was discovered four years ago by the Panoramic Survey Telescope and Rapid Response System in Hawaii. Researchers have analyzed it for years. They published the results of their study in the journal Nature Astronomy.
SN2016aps is twice as bright and has twice as much energy as a typical supernova. According to researchers, it was so bright that at the beginning scientists couldn’t even see the galaxy where it was located until the supernova’s light had faded.
"In a typical supernova, the radiation is less than 1 percent of the total energy. But in SN2016aps, we found the radiation was five times the explosion energy of a normal-sized supernova. This is the most light we have ever seen emitted by supernova", said Dr. Matt Nicholl, lead author of the study of the School of Physics and Astronomy and the Institute of Gravitational Wave Astronomy at the University of Birmingham.
Besides the unprecedented levels of radiation, the mass of the SN2016aps is enormous. Usually supernovae have 8 to 15 solar masses (a mass bigger than the mass of the Sun). SN2016aps’s mass is between 50 to 100 solar masses.
Scientists suspect that it could be a "pulsation pair-stability" supernova, a scientific hypothesis that has not been yet verified.
"Stars with extremely large mass undergo violent pulsations before they die, shaking off a giant gas shell. This can be powered by a process called the pair stability, which has been a topic of speculation for physicists for the last 50 years”, said Dr. Nicholl. "If the supernova gets the timing right, it can catch up to this shell and release a huge amount of energy in the collision. We think this is one of the most compelling candidates for this process yet observed, and probably the most massive."
Researchers say that the SN2016aps could be the result of two stars merging together before the explosion. Scientists note that with the help of NASA’s James Webb Space telescope they will be able to study similar events so far away "that we can look back in time to the deaths of the very first stars in the Universe".