Solar cycle 21
From Infogalactic: the planetary knowledge core
| Solar cycle 21 | |
|---|---|
The Sun, recorded at the H-alpha wavelength, during solar cycle 21 (28 April 1980).
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| Sunspot Data | |
| Start date | June 1976 |
| End date | September 1986 |
| Duration (years) | 10.3 |
| Max count | 164.5 |
| Max count month | December 1979 |
| Min count | 12.3 |
| Spotless days | 273 |
| Cycle chronology | |
| Previous cycle | Solar cycle 20 (1964-1976) |
| Next cycle | Solar cycle 22 (1986-1996) |
Solar cycle 21 was the 21st solar cycle since 1755, when extensive recording of solar sunspot activity began.[1][2] The solar cycle lasted 10.3 years, beginning in June 1976 and ending in September 1986. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve-month period) observed during the solar cycle was 164.5, in December 1979 (the second-highest peak on record), and the minimum was 12.3.[3] There were a total of 273 days with no sunspots during this cycle.[4][5][6] The largest solar flare of this cycle (X15) occurred on July 11, 1978.[7]
See also
References
- ↑ Kane, R.P. (2002). "Some Implications Using the Group Sunspot Number Reconstruction". Solar Physics 205(2), 383-401.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ SIDC Monthly Smoothed Sunspot Number. "[1]"
- ↑ Spotless Days. "[2]"
- ↑ What's Wrong with the Sun? (Nothing) more information: Spotless Days. "[3]"
- ↑ Solaemon's Spotless Days Page. "[4]"
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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