Jawaan!

Japanese scientists journeyed to Antarctica to recover evidence of alterations to Earth’s atmosphere caused in medieval times by supernovae recorded by scholars – including obscure Irish monasteries where monks later interpreted them signs of the Antichrist . No, this isn’t the plot of the next Dan Brown novel (or a Dan Brow fanfiction written by an X-Files addict): this is real science. Supernovae release terrific amounts of energy, as in “If one happened too close, the planet would be sterilized” truly terror-inducing terrific.  Some of this energy is fired off as gamma rays, which can travel thousands of light-years and still pack enough of a punch after to alter the atmosphere – which is exactly what happened in 1006 and again in 1054, when gamma rays blasted the upper atmosphere and created spikes in NO3 levels.  There was also quite a lot of visible light, creating a star visible even during the day which was noted by various Chinese, Egyptian and even monastic records

Original post:
Searching for Traces of an Ancient Supernova in Antarctica