Solar cycle 2

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Solar cycle 2
Wilson effect original.jpg
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 193.0
Max count month September 1769
Min count 18.6
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 (SIDC formula) observed during the solar cycle was 193.0 (September 1769), and the starting minimum was 18.6.[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]"