An international team of astronomers led by the University of Birmingham, along with help from experts at Harvard University, Northwestern University, and Ohio University, has discovered a supernova called SN2016aps. The team says that the supernova is at least twice as bright and energetic as any previously recorded. The scientists also believe that the supernova they have discovered is likely much more massive than any other recorded supernova.
The team says that SN2016aps may be an example of an extremely rare “pulsational pair-instability” supernova that was possibly formed from two massive stars that merged before the explosion. The team says that such an event had only existed in theory and hadn’t been confirmed by observations. One of the researchers, Dr. Matt Nicholl from the University of Birmingham, says that supernovae are measured using two scales, the total energy of the explosion and the amount of energy emitted as visible light or radiation.
He says that in a typical supernova, radiation is less than one percent of the total energy. However, in SN2016aps, the team found that radiation was five times the explosive energy of a normal-sized supernova. The team also says that the supernova is producing the most light ever seen emitted by such a phenomenon.
The teams says for the supernova to be so bright that the explosion creating it must’ve been much more energetic than usual. Examination of the light spectrum determined that the explosion was powered by a collision between the supernova and a massive shell of gas that was shed by the star in the years before it exploded. The team says one thing that made this particular supernova standout for observation was that it appeared to be in the cosmic “middle of nowhere” while most supernovae are in massive galaxies.
The team says it was unable to see the galaxy where the supernova was born until after its light faded. The team observed the explosion for two years until the light faded to one percent of its peak brightness. There were able to calculate that the supernova was between 50 and 100 times greater than the mass the Sun. A typical supernova is between eight and 15 solar masses.