SN 393
The Wěi asterism appears in the lower half of the Scorpius constellation
|
|
| Other designations | SN 393 |
|---|---|
| Event type |
Supernova 
|
| Spectral class | Type II/Ib |
| Observation | |
| Date | 27 February− 28 March 393 22 October− 19 November 393 CE |
| Location | |
| Constellation | Scorpius |
| Right ascension | 17h 14m |
| Declination | −39.8° |
| Epoch | J2000 |
| Galactic coordinates | G347.4−00.6° |
| Distance | 1 kpc (3×103 ly) |
| Remnant | Shell |
| Host | Milky Way |
| Characteristics | |
| Energetics | |
| Peak apparent magnitude | −1 |
| See also | |
| Preceded by | SN 386 |
| Followed by | SN 1006 |
|
[]
|
|
SN 393 is the modern designation for a probable supernova that was reported by the Chinese in the year 393 CE. An extracted record of this astronomical event was translated into English as follows:
A guest star appeared within the asterism Wěi during the second lunar month of the 18th year of the Tai-Yuan reign period, and disappeared during the ninth lunar month.
The second lunar month mentioned in the record corresponds to the period 27 February to 28 March 393 CE, while the ninth lunar month ran from 22 October to 19 November 393 CE. The bowl-shaped asterism named Wěi is formed by the tail of the modern constellation Scorpius. 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., whose lengthy duration suggests the source was a supernova.
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. At the time, there were only seven possible candidate supernova remnants near where SN 393 was observed. Assuming maximum –1 magnitude occurred close to 10,000 pc (33,000 ly) away, this immediately ruled out four possible candidates. Another discounted remnant was G350.0-1.8, as the expectant expansion rate indicated the supernova occurred around 8,000 years ago. Of the two remaining sources, G348.5+0.1 and G348.7+0.3, were both at the required 10,000 pc. distance and also each had estimated ages of 1,500 years. 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.
...
Wikipedia