Solar flares on April 21, 2002
The most powerful solar flare in 24 hours
X1.5 (very strong) flare - April 21 at 1:51 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+00
List of solar flares for April 21, 2002
The total number of solar flares of class C and higher — 5 flares
C class — 4 | M class — 0 | X class — 1
| Class | begin | max | end | region |
|---|---|---|---|---|
| C3.4 | 21:51 | 21:56 | 21:58 | — |
| C2.9 | 20:11 | 20:16 | 20:18 | — |
| C8.3 | 17:37 | 18:06 | 18:24 | — |
| C7.9 | 17:25 | 17:30 | 17:33 | — |
| X1.5 | 00:43 | 01:51 | 02:38 | 9906 |