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X1.2 solar flare on 1981-04-28
ClassX1.2NOAA report
Peak21:141981-04-28 UTC
Duration99 min
Peak flux1.2e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 319 / 491 |
| Rank in year | 27 / 4022 |
| Other M/X flares that day | 0 |
| 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
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.
← X5.5 1981-04-27M9.5 1981-05-04 →
About this page
A X1.2 flare that began 1981-04-28 21:04 UTC; No. 27 of 4,022 C-class-or-larger flares in 1981.