Solar flares on April 21, 2013
The most powerful solar flare in 24 hours
C4.5 (normal) flare - April 21 at 8:39 PM
Solar activity index
Value as of the end of the day on April 21, 2013
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from April 20, 2013 to April 21, 2013
Time zone — UTC+02 (Vienna) — summer time
List of solar flares for April 21, 2013
The total number of solar flares of class C and higher — 16 flares
C class — 16 | M class — 0 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C2.7 | 21:59 | 22:15 | 22:32 | 1723 |
| C4.5 | 20:35 | 20:39 | 20:42 | 1726 |
| C2.9 | 18:00 | 18:03 | 18:06 | 1726 |
| C2.2 | 16:16 | 16:20 | 16:23 | 1726 |
| C1.0 | 13:38 | 14:03 | 14:09 | 1726 |
| C1.0 | 12:52 | 12:55 | 12:57 | 1726 |
| C1.8 | 12:21 | 12:24 | 12:26 | 1726 |
| C2.5 | 11:20 | 11:23 | 11:27 | 1726 |
| C1.3 | 09:30 | 09:34 | 09:40 | 1726 |
| C2.7 | 07:57 | 08:00 | 08:02 | 1726 |
| C1.4 | 07:04 | 07:14 | 07:18 | 1726 |
| C1.0 | 04:56 | 05:00 | 05:02 | 1726 |
| C3.6 | 03:02 | 03:09 | 03:16 | 1726 |
| C1.3 | 00:46 | 00:52 | 00:59 | 1726 |
| C1.1 | 00:24 | 00:29 | 00:33 | 1726 |
| C1.1 | 00:09 | 00:13 | 00:18 | 1726 |