Solar flares on October 21, 2011
The most powerful solar flare in 24 hours
M1.3 (strong) flare - October 21 at 3:00 PM
Solar activity index
Value as of the end of the day on October 21, 2011
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from October 20, 2011 to October 21, 2011
Time zone — UTC+02 (Zagreb) — summer time
List of solar flares for October 21, 2011
The total number of solar flares of class C and higher — 4 flares
C class — 3 | M class — 1 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C2.7 | 19:00 | 19:04 | 19:10 | 1319 |
| C1.5 | 15:40 | 15:44 | 15:46 | 1319 |
| M1.3 | 14:53 | 15:00 | 15:08 | 1319 |
| C2.4 | 10:53 | 10:57 | 11:02 | 1324 |