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M8.7 solar flare on 2023-09-21
ClassM8.7GOES-16 science data
Peak12:542023-09-21 UTC
Duration19 min
Peak flux8.7e-05W/m²
| Comparison | Value |
|---|---|
| Rank in year | 17 / 3209 |
| Other M/X flares that day | 0 |
| M/X flares that month | 34 |
| Solar cycle | Cycle 25 |
Compared with the strongest flares of 2023
X4.9
X2.8
X2.2
X2.0
X1.9
X1.6
X1.4
X1.2
X1.2
X1.1
X1.0
X1.0
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.
← M8.2 2023-09-20M9.9 2023-11-28 →
About this page
A M8.7 flare that began 2023-09-21 12:42 UTC; No. 17 of 3,209 C-class-or-larger flares in 2023.