Solar dynamo
type: Concept
broader: Solar cycle

Active sun
type: Concept
broader: Solar cycle

Helioseismology
type: Concept
narrower: Solar cycle

Sunspot cycle
type: Concept
broader: Solar cycle

Quiet sun
type: Concept
broader: Solar cycle

Solar cycle
modified: 2020-11-19T15:46:12.14Z
modified: 2020-11-19T15:46:01.601Z
alternative label: Solar cycle variations
alternative label: Solar magnetic activity cycle
alternative label: Sun cycles
alternative label: Solar activity cycles
alternative label: Sun cycle
narrower: Solar dynamo
narrower: Active sun
narrower: Sunspot cycle
narrower: Quiet sun
definition: The periodic variation in frequency or number of solar active events (sunspots, prominences, flares, and other solar activity) occurring with an interval of about 11 years. The solar cycle was discovered in 1843 by Samuel Heinrich Schwabe (1789-1875), a German apothecary and amateur astronomer, who after 17 years of observations noticed a periodic variation in the average number of sunspots seen from year to year on the solar disk. Solar cycle numbering goes back to the 18th century, when the Cycle 1 peak occurred in 1760. Cycle 23 peaked in 2000, and the following Cycle 24 will reach its maximum in 2013.
broader: Helioseismology
type: Concept
contributor: AAS Frey.Katie