Solar flares on October 21, 2001
The most powerful solar flare in 24 hours
M2.5 (strong) flare - October 21 at 7:36 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+08 (Ulan-Ude)
List of solar flares for October 21, 2001
The total number of solar flares of class C and higher — 14 flares
C class — 12 | M class — 2 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C2.5 | 21:11 | 21:26 | 21:31 | 9670 |
| M2.5 | 19:12 | 19:36 | 19:48 | 9661 |
| C2.7 | 15:53 | 15:57 | 16:00 | — |
| C2.7 | 13:44 | 13:47 | 13:51 | — |
| M1.3 | 13:09 | 13:18 | 13:27 | — |
| C7.8 | 12:33 | 12:37 | 12:39 | — |
| C1.4 | 11:21 | 11:24 | 11:28 | — |
| C1.9 | 09:47 | 09:51 | 09:54 | — |
| C2.1 | 08:28 | 08:31 | 08:33 | — |
| C4.3 | 08:04 | 08:11 | 08:15 | 9672 |
| C2.5 | 06:33 | 06:38 | 06:41 | 9674 |
| C3.3 | 06:04 | 06:11 | 06:13 | — |
| C3.0 | 05:44 | 05:47 | 05:54 | 9670 |
| C4.6 | 05:07 | 05:12 | 05:15 | 9674 |