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X1.0 solar flare on 1981-02-17
ClassX1.0NOAA report
Peak21:501981-02-17 UTC
Duration330 min
Peak flux1.0e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 393 / 491 |
| Rank in year | 31 / 4022 |
| Other M/X flares that day | 1 |
| M/X flares that month | 44 |
| Solar cycle | Cycle 21 |
| Position on disk | N20W20 |
| Active region | AR 2941 (11 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 |
|---|---|---|---|---|---|---|
| 17:58 | 19:13 | 134 | M1.5 | N12W06 | 2947 |
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 1981-01-28M8.3 1981-02-19 →
About this page
A X1.0 flare that began 1981-02-17 18:12 UTC; No. 31 of 4,022 C-class-or-larger flares in 1981.