Solar Flare WatchHome › Flare history › 1981
X5.5 solar flare on 1981-04-27
ClassX5.5NOAA report
Peak08:201981-04-27 UTC
Duration145 min
Peak flux5.5e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 47 / 491 |
| Rank in year | 2 / 4022 |
| Other M/X flares that day | 1 |
| M/X flares that month | 87 |
| Solar cycle | Cycle 21 |
| Active region | AR 3049 (30 flares) |
Compared with the strongest flares of 1981
X5.9
X5.5
X4.0
X3.6
X3.5
X3.1
X3.0
X2.7
X2.6
X2.5
X2.4
X2.3
Other M/X flares that day
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 22:56 | 00:00 | 24 | M3.4 | N15W90 | 3049 |
All times UTC. Until June 2017 classes are NOAA's reports of the time (GOES-15 and earlier included a 0.7 scaling factor); later classes come from calibrated GOES-16/18 data, so the same flare reads about 1.4× larger. Do not compare the two periods directly.
← X1.2 1981-04-26X1.2 1981-04-28 →
About this page
A X5.5 flare that began 1981-04-27 07:20 UTC; No. 2 of 4,022 C-class-or-larger flares in 1981.