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X1.9 solar flare on 1981-04-04
ClassX1.9NOAA report
Peak05:031981-04-04 UTC
Duration3 min
Peak flux1.9e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 202 / 491 |
| Rank in year | 18 / 4022 |
| Other M/X flares that day | 4 |
| M/X flares that month | 87 |
| Solar cycle | Cycle 21 |
| Position on disk | S44W85 |
| Active region | AR 2999 (23 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 |
|---|---|---|---|---|---|---|
| 08:02 | 08:09 | 41 | M2.0 | N02E34 | 3022 | |
| 08:30 | 08:35 | 21 | M8.2 | N36E72 | 3027 | |
| 10:00 | 10:05 | 11 | M2.1 | – | – | |
| 21:48 | 22:06 | 52 | M1.0 | N18E71 | 3027 |
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.
← M8.3 1981-04-03M8.2 1981-04-04 →
About this page
A X1.9 flare that began 1981-04-04 05:02 UTC; No. 18 of 4,022 C-class-or-larger flares in 1981.