A mysterious remnant from a rare type of supernova recorded in 1181 has been explained for the first time. Two white dwarf stars collided, creating a temporary ‘guest star,’ now labeled supernova (SN) 1181, which was recorded in historical documents in Japan and elsewhere in Asia. However, after the star dimmed, its location and structure remained a mystery until a team pinpointed its location in 2021. Now, through computer modeling and observational analysis, researchers have recreated the structure of the remnant white dwarf, a rare occurrence, explaining its double shock formation. They also discovered that high-speed stellar winds may have started blowing from its surface within just the past 20-30 years. This finding improves our understanding of the diversity of supernova explosions, and highlights the benefits of interdisciplinary research, combining history with modern astronomy to enable new discoveries about our galaxy.