This "guest star" was observed by Chinese astronomers in the Book of Later Han (后汉书),[3] and might have been recorded in Roman literature.

The Book of Later Han gives the following description: In the 2nd year of the epoch Zhongping [中平], the 10th month, on the day Guihai [癸亥] [December 7, Year 185], a 'guest star' appeared in the middle of the Southern Gate [南門] [an asterism consisting of ε Centauri and α Centauri], The size was half a bamboo mat.

[5]The gaseous shell RCW 86 is probably the supernova remnant of this event and has a relatively large angular size of roughly 45 arc minutes[1] (larger than the apparent size of the full moon, which varies from 29 to 34 arc minutes).

The findings show that the stellar explosion took place in a hollowed-out cavity, allowing material expelled by the star to travel much faster and farther than it would have otherwise.

[7] Differing modern interpretations of the Chinese records of the guest star have led to quite different suggestions for the astronomical mechanism behind the event, from a core-collapse supernova[7] to a distant, slow-moving comet[8] – with correspondingly wide-ranging estimates of its apparent visual magnitude (−8 to +4).