Solar cycle 2

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Solar cycle 2
Drawing of a sunspot from 1774, illustrating the Wilson effect
Sunspot Data
Start date June 1766
End date June 1775
Duration (years) 9
Max count 115.8
Max count month September 1769
Min count 7.2
Cycle chronology
Previous cycle Solar cycle 1 (1755-1766)
Next cycle Solar cycle 3 (1775-1784)

Solar cycle 2 was the second solar cycle since 1755, when extensive recording of solar sunspot activity began.[1][2] The solar cycle lasted 9 years, beginning in June 1766 and ending in June 1775. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve-month period) observed during the solar cycle was 115.8 (September 1769), and the minimum was 7.2.[3]

Sunspot observations by Alexander Wilson during this period established the Wilson effect.

See also[edit]


  1. ^ Kane, R.P. (2002). "Some Implications Using the Group Sunspot Number Reconstruction". Solar Physics 205(2), 383-401.
  2. ^ "The Sun: Did You Say the Sun Has Spots?". Space Today Online. Retrieved 12 August 2010. 
  3. ^ SIDC Monthly Smoothed Sunspot Number. "[1]"