Space

The Sun draws butterflies

Sunspots are not scattered at random. Plot each one by the latitude it appears at — north above the line, south below — and a pattern surfaces that nobody designed: every eleven years a new cycle opens near 30°, then marches steadily toward the equator and dies there as the next one opens above it. Brightness is how much spotted area sat in that strip of the Sun. Tap or hover anywhere.

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Data & source

Source: the Greenwich Photoheliographic Results and their USAF/NOAA continuation, compiled by NASA Marshall · public domain · fetched —. One column per solar rotation (27.3 days) from 1874 to 2016 — that is where this compilation ends, so the current cycle is not here. Latitudes are the file's 50 equal-area strips (equal steps in the sine of latitude); values are sunspot area within each strip, in millionths of the visible hemisphere. Cycle numbers are marked at their accepted minima.