Abstract
The guest star of A.D. 185 is possibly the earliest recorded supernova, and the radio source RCW 86 is believed to be its remnant. However, a restudy of ancient Chinese literature suggests that RCW 86 is unrelated to the guest star, which probably had a visible duration of only 7 months and appeared between β and ∈ Centauri, instead of the previously proposed 20-month duration and a location between α and β Centauri.