This asterism consists of the stars in Scorpius designated ε, μ, ζ, η, θ, ι, κ, λ and ν.

The guest star reached an estimated apparent magnitude of −1 and was visible for about eight months before fading from sight,[5] whose lengthy duration suggests the source was a supernova.

[7][6] Before 1975, the observation made by the Chinese between February and March 393 CE was considered to be likely a bright nova with a secondary maximum.

[5] If true, it seems unlikely such supernovae would be visible to the naked eye over eight months, especially because they occurred close to a particularly dusty part of the galactic plane.

Possible (and certainly not the only) candidates in the Chinese constellation of Wei are according to:[7] During 1996, the ROSAT All Sky Survey discovered another nearby supernova remnant, RX J1713.7-3946, which two years later, was suggested as a better match for SN 393.