Solar flares on April 21, 2002
The most powerful solar flare in 24 hours
X1.5 (very strong) flare - April 21 at 3:51 AM
Solar activity index
Value as of the end of the day on April 21, 2002
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from April 20, 2002 to April 21, 2002
Time zone — UTC+02 (Monaco) — summer time
List of solar flares for April 21, 2002
The total number of solar flares of class C and higher — 6 flares
C class — 5 | M class — 0 | X class — 1
| Class | begin | max | end | region |
|---|---|---|---|---|
| C3.4 | 23:51 | 23:56 | 23:58 | — |
| C2.9 | 22:11 | 22:16 | 22:18 | — |
| C8.3 | 19:37 | 20:06 | 20:24 | — |
| C7.9 | 19:25 | 19:30 | 19:33 | — |
| X1.5 | 02:43 | 03:51 | 04:38 | 9906 |
| C1.9 | 01:23 | 01:26 | 01:28 | — |