Cosmic crime scene reveals ancient supernova aftermath of dead star merger

Two white orbs on the left side of the screen. In a boxout toward the bottom right, there's a red and purple splotchy image with a yellow glowing center.

The ultimate cosmic "cold case" has lingered for 843 years — and now, space detectives may have solved it at last. In 1181 AD, as the Genpei War raged in Japan, a mystery "guest star" briefly flashed over Asia's skies. Astronomers had puzzled over the brief event until 2021, when a team of researchers tracked it to its location in the cosmos. Yet, the cause of the event, now designated supernova (SN) 1181, remained shrouded in mystery.

That was until a team of scientists used computer modeling and observational analysis to recreate the event, finding it was a supernova caused by two "dead star" white dwarfs colliding together. The structure of the remnant white dwarf and leftovers of double shock formation were left behind by the rare occurrence of these two colliding white dwarfs.