Solar flares on October 21, 2013
The most powerful solar flare in 24 hours
M1.0 (strong) flare - October 21 at 7:22 PM
Solar activity index
Value as of the end of the day on October 21, 2013
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from October 20, 2013 to October 21, 2013
Time zone — UTC-05 (San Antonio) — summer time
List of solar flares for October 21, 2013
The total number of solar flares of class C and higher — 16 flares
C class — 15 | M class — 1 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C2.1 | 23:40 | 23:44 | 23:46 | 1875 |
| C4.0 | 23:12 | 23:21 | 23:25 | 1875 |
| C4.3 | 22:31 | 22:37 | 22:45 | 1875 |
| C1.7 | 20:59 | 21:03 | 21:07 | 1875 |
| C1.4 | 20:31 | 20:35 | 20:41 | 1875 |
| M1.0 | 19:14 | 19:22 | 19:28 | 1875 |
| C1.0 | 19:05 | 19:09 | 19:13 | — |
| C2.7 | 18:02 | 18:11 | 18:15 | 1875 |
| C2.0 | 17:31 | 17:46 | 17:58 | 1875 |
| C1.5 | 15:56 | 16:00 | 16:07 | 1875 |
| C1.6 | 15:20 | 15:34 | 15:39 | — |
| C2.4 | 10:40 | 11:10 | 11:16 | 1875 |
| C1.1 | 09:33 | 09:44 | 10:36 | 1877 |
| C1.0 | 04:19 | 04:22 | 04:25 | 1877 |
| C1.6 | 03:09 | 03:13 | 03:17 | 1875 |
| C1.7 | 02:06 | 02:14 | 02:18 | — |