In 1181 CE, astronomers in China and Japan recorded a new, short-lived star in the constellation Cassiopeia. After burning for nearly six months, this historic supernova disappeared from the naked eye. It was only in 2013 that an amateur astronomer identified a nebula in the vicinity of that supernova, and, in the years since, astronomers have collected evidence that identifies the object, known as Pa 30, as the remnants of that 1181 supernova. Now, astronomers have mapped the supernova remnant, revealing an unusual dandelion-like structure (shown in an artist’s conception above and below). Filaments of sulfur project outward from a dusty central region that houses the remains of the original star. Normally, a supernova destroys its original star, but this was a Type Iax supernova, a “failed” explosion that left behind a hot, inflated star that may eventually cool into a white dwarf star.
Why the supernova remnant has this strange shape remains unclear. Scientists speculate that shock waves may have helped concentrate sulfur into these clumpy filaments. The material’s velocity suggests a ballistic trajectory (meaning, essentially, that it has neither sped up nor slowed down since the original explosion). Winding the trajectory backwards pegs their origin to 1181, helping confirm that Pa 30 is, indeed, the remains of that 1181 supernova. (Image and video credit: W.M. Keck Observatory/A. Makarenko; research credit: R. Fesen et al.; via Gizmodo)