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X1.7 solar flare on 1984-04-21
ClassX1.7NOAA report
Peak20:171984-04-21 UTC
Duration25 min
Peak flux1.7e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 232 / 491 |
| Rank in year | 6 / 1262 |
| Other M/X flares that day | 6 |
| M/X flares that month | 39 |
| Solar cycle | Cycle 21 |
| Active region | AR 4474 (100 flares) |
Compared with the strongest flares of 1984
X13.0
X10.1
X4.1
X2.7
X2.3
X1.7
X1.0
M7.5
M7.2
M7.1
M6.3
M5.7
Other M/X flares that day
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 01:57 | 02:05 | 38 | M1.2 | S08E87 | 4474 | |
| 02:35 | 02:55 | 51 | M1.5 | N04W75 | 4471 | |
| 07:30 | 07:30 | 8 | M1.2 | S14E83 | 4474 | |
| 10:28 | 10:37 | 20 | M2.4 | – | – | |
| 13:04 | 13:11 | 16 | M1.0 | – | 4474 | |
| 14:20 | 14:58 | 70 | M1.4 | S09E76 | 4474 |
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.
← M5.7 1984-04-20M5.0 1984-04-22 →
About this page
A X1.7 flare that began 1984-04-21 20:09 UTC; No. 6 of 1,262 C-class-or-larger flares in 1984.