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X1.0 solar flare on 1991-03-21
ClassX1.0NOAA report
Peak20:221991-03-21 UTC
Duration71 min
Peak flux1.0e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 412 / 491 |
| Rank in year | 47 / 3297 |
| Other M/X flares that day | 7 |
| M/X flares that month | 123 |
| Solar cycle | Cycle 22 |
| Position on disk | S13E29 |
| Active region | AR 6555 (79 flares) |
Compared with the strongest flares of 1991
X12.0
X12.0
X12.0
X12.0
X12.0
X10.0
X10.0
X9.4
X7.1
X6.1
X5.5
X5.3
Other M/X flares that day
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 00:36 | 00:50 | 34 | M1.5 | S23E51 | 6555 | |
| 05:58 | 05:59 | 8 | M1.6 | S24E53 | – | |
| 08:18 | 08:18 | 18 | M2.7 | S09W66 | – | |
| 10:29 | 10:41 | 22 | M2.6 | S24E48 | 6555 | |
| 12:14 | 12:48 | 52 | M1.1 | S19E41 | 6555 | |
| 15:03 | 15:28 | 47 | M1.7 | S24E44 | 6555 | |
| 23:37 | 23:43 | 109 | M5.4 | S25E40 | 6555 |
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.
← M7.0 1991-03-20M5.4 1991-03-21 →
About this page
A X1.0 flare that began 1991-03-21 20:20 UTC; No. 47 of 3,297 C-class-or-larger flares in 1991.