1,000 year old supernova may be recorded in Antarctic ice

In an analysis of the nitrate content of an ice core drilled at Dome Fuji station in Antarctica, scientists have found what may be chemical traces of supernovae that exploded a thousand years ago.
According to a report in New Scientist, the analysis was done by Yuko Motizuki of the RIKEN research institute in Wako, Japan, and colleagues.