SP-402 A New Sun: The Solar Results From Skylab

THE SUNSPOT CYCLE, 1610-1976. Sunspots come and go on the Sun in an irregular cycle of about 11 years, with some obvious long-term changes.

 

THE SUNSPOT CYCLE, 1610-1976. Sunspots come and go on the Sun in an irregular cycle of about 11 years, with some obvious long-term changes. Annual mean sunspot numbers (an average measure of spottedness of the Sun) are shown here for each year since the discovery of the telescope. Data on the earlier parts of the graph are less reliable than in later periods.

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