SN 1885A
The visual band light curve of S Andromedae, adapted from Patchett et al. (1985) | |
| Event type | Supernova, supernova remnant, near-IR source, variable star |
|---|---|
| I pec | |
| Date | 20 August 1885 UTC |
| Constellation | Andromeda |
| Right ascension | 00h 42m 43.11s |
| Declination | +41° 16′ 04.2′′ |
| Epoch | J2000.0 |
| Galactic coordinates | 121.1702 -21.5741 |
| Distance | 2.6 Mly |
| Remnant | Unknown |
| Host | Andromeda Galaxy |
| Progenitor | Unknown |
| Progenitor type | Unknown |
| Colour (B-V) | +1.3 ~ +0.6 |
| Notable features | First and only supernova observed in Andromeda; first extragalactic supernova observed; closest type Ia observed |
| Peak apparent magnitude | +6 |
| Other designations | SN 1885A, HR 182, 2MASS J00424312+4116032, BD+40 147a, S And, TIC 438234291, AAVSO 0037+40, EV* M31 V0894 |
| Preceded by | SN 1604 (observed), Cassiopeia A (unobserved, c. 1680), G1.9+0.3 (unobserved, c. 1868) |
| Followed by | SN 1895B |
SN 1885A (also S Andromedae) was a supernova in the Andromeda Galaxy, the only one seen in that galaxy so far by astronomers. It was the first supernova ever seen outside the Milky Way, though it was not appreciated at the time due to how far away it was. It is also known as "Supernova 1885".