1181 supernova
Calibration case. Open for 800 years until the Pa 30 nebula was identified as the remnant in 2021.
How it connects
This mystery we read it in
Ritter et al. 2021, Pa 30 as the remnant of SN 1181
This mystery has this clue
Nebula Pa 30
This mystery has this clue
Guest star in Cassiopeia, 1181, 185 days