Solar flares on October 21, 2001
The most powerful solar flare in 24 hours
M2.5 (strong) flare - October 21 at 12:36 PM
Solar activity index
Value as of the end of the day on October 21, 2001
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from October 20, 2001 to October 21, 2001
Time zone — UTC+01 (Dublin) — summer time
List of solar flares for October 21, 2001
The total number of solar flares of class C and higher — 11 flares
C class — 9 | M class — 2 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C2.0 | 21:54 | 21:58 | 22:00 | — |
| C2.5 | 14:11 | 14:26 | 14:31 | 9670 |
| M2.5 | 12:12 | 12:36 | 12:48 | 9661 |
| C2.7 | 08:53 | 08:57 | 09:00 | — |
| C2.7 | 06:44 | 06:47 | 06:51 | — |
| M1.3 | 06:09 | 06:18 | 06:27 | — |
| C7.8 | 05:33 | 05:37 | 05:39 | — |
| C1.4 | 04:21 | 04:24 | 04:28 | — |
| C1.9 | 02:47 | 02:51 | 02:54 | — |
| C2.1 | 01:28 | 01:31 | 01:33 | — |
| C4.3 | 01:04 | 01:11 | 01:15 | 9672 |