AAVSO: American Association of Variable Star Observers
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Current Phase of the Sunspot Cycle (Abstract)

Volume 29 number 1 (2001)

Thomas Cragg

Abstract

(Abstract only) A brief introduction of how sunspot numbers are derived is discussed. A 200- year sunspot curve is presented and discussed, with emphasis on the alternating height of cycle maximum—one cycle higher, the next cycle lower, the next cycle higher, etc.—since 1850. Predictions of the current cycle maximum are also presented, demonstrating that the chances of continuation of the 150-year alternation are in doubt