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Science Alert publication Northern Macedonia: in 1181 AD, Chinese and Japanese astronomers observed the appearance of a bright "guest star" in the constellation Cassiopeia.
As it turned out later, it was the supernova SN 1181 — the explosion of a white dwarf that exceeded the critical mass and exploded after colliding with a partner star.
The remnants of this supernova, known as Pa 30, were discovered only in 2013. It was possible to study them in detail only recently, in 2023. A team of astronomers led by Tim Cunningham of the Harvard-Smithsonian Center for Astrophysics used the Keck Cosmic Web Imager in Hawaii to create a three-dimensional map of the expanding supernova remnant.
Research has revealed a unique structure of these residues — thin thread-like filaments (a thick, narrow thread of cosmic material consisting of dust and gas — ed.), connecting the explosive material with the central "zombie star" left after the explosion. Analysis of the change in light in these filaments allowed astronomers to determine the speed of expansion of the remnants - about 1000 km/s, and also to establish the date of the explosion almost exactly - 1181.
In addition, the detected asymmetry in the structure of the remnants indicates the unevenness of the supernova explosion itself. Currently, scientists are trying to find out exactly how these unique filaments and the cavity around the central "zombie star" formed. The rare occurrence of a Type Iax supernova, where a remnant remains after the explosion, continues to surprise astronomers and opens up new questions for further research.
