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X3.9 solar flare on 1991-03-13
ClassX3.9NOAA report
Peak15:591991-03-13 UTC
Duration48 min
Peak flux3.9e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 74 / 491 |
| Rank in year | 14 / 3297 |
| Other M/X flares that day | 3 |
| M/X flares that month | 123 |
| Solar cycle | Cycle 22 |
| Position on disk | S12E41 |
| Active region | AR 6545 (57 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 |
|---|---|---|---|---|---|---|
| 02:53 | 03:10 | 51 | M9.7 | S11E48 | – | |
| 07:30 | 07:33 | 12 | M1.4 | S09E46 | 6545 | |
| 08:00 | 08:04 | 134 | X1.3 | S11E43 | 6545 |
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.
← X1.3 1991-03-13X1.8 1991-03-14 →
About this page
A X3.9 flare that began 1991-03-13 15:28 UTC; No. 14 of 3,297 C-class-or-larger flares in 1991.