Solar flares on October 21, 2004
The most powerful solar flare in 24 hours
C9.9 (normal) flare - October 21 at 7:48 PM
Solar activity index
Value as of the end of the day on October 21, 2004
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from October 20, 2004 to October 21, 2004
Time zone — UTC+00
List of solar flares for October 21, 2004
The total number of solar flares of class C and higher — 7 flares
C class — 7 | M class — 0 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C9.9 | 19:24 | 19:48 | 19:56 | 687 |
| C4.3 | 15:12 | 15:22 | 15:27 | 682 |
| C1.7 | 14:27 | 14:42 | 15:04 | 682 |
| C5.2 | 06:44 | 06:53 | 06:57 | 687 |
| C2.0 | 05:05 | 05:12 | 05:15 | 687 |
| C4.3 | 02:10 | 02:15 | 02:18 | 687 |
| C7.8 | 00:18 | 00:40 | 00:52 | 687 |