butterfly diagram

astronomy

Also known as: Maunder butterfly diagram

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Last updated

June 22, 2026

Quick Summary

The "butterfly diagram" in astronomy refers to a chart that illustrates the latitude drift of sunspots during each solar cycle. This diagram, charted by Annie Russel Maunder, shows how sunspots appear in middle latitudes at the beginning of a cycle and progressively move closer to the Sun's equator as the cycle progresses towards its maximum activity and then declines.1

The diagram's name comes from the wing-like shapes formed by the graph of sunspot activity over time and latitude. Each solar cycle begins with small spots appearing in mid-latitudes, and as the cycle advances, new spots emerge closer to the equator. This pattern is linked to the reversal of magnetic polarity in sunspots every 11 years, with a complete magnetic cycle taking 22 years.12

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sunspot
…chart is sometimes called the butterfly diagram because of the winglike shapes assumed by the graph. Each solar cycle begins with small spots appearing in middle latitudes of the Sun. Succeeding spots appear progressively closer to the Sun’s equator as the cycle reaches its maximum level of activity and declines.
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…chart is sometimes called the butterfly diagram because of the winglike shapes assumed by the graph. Each solar cycle begins with small spots appearing in middle latitudes of the Sun. Succeeding spots appear progressively closer to the Sun’s equator as the cycle reaches its maximum level of activity and declines.
Read More