Astronomers find nebula that lit up Medieval skies more than 800 years ago

NASA astronomers have finally found and photographed the remnants of a supernova that shined bright in the sky for six months more than 800 years ago.

In the year 1181 a rare supernova explosion appeared in the night sky, staying visible for 185 consecutive days.

Historical records show that the supernova looked like a temporary ‘star’ in the constellation Cassiopeia shining as bright as Saturn.

Back then it would have been seen by Henry II of England, and his son Richard, later the Lionheart. It would have also been seen by Richard’s great military rival Saladin, who ruled Syria and Egypt. Ever since, scientists have tried to find the supernova’s remnant. At first it was thought that this could be the nebula around the pulsar — the dense core of a collapse star — named 3C 58.

However closer investigations revealed that the pulsar is older than supernova 1181. In the last decade, another contender was discovered; Pa 30 is a nearly circular nebula with a central star in the constellation Cassiopeia. It is pictured here combining images from several telescopes. This composite image uses data across the electromagnetic spectrum and shows a spectacular new view of the supernova remnant.

This allows us to marvel at the same object that appeared in our ancestors’ night sky more than 800 years ago. X-ray observations by ESA’s XMM-Newton (blue) show the full extent of the nebula and NASA’s Chandra X-ray Observatory (cyan) pinpoints its central source. The nebula is barely visible in optical light but shines bright in infrared light, collected by NASA’s Wide-field Infrared Space Explorer (red and pink).