butterfly diagramA plot of heliographic latitude of sunspots versus time, developed by E. Walter Maunder in 1904 to illustrate the solar cycle. It shows how spots move from higher latitudes (30° to 40° N or S) toward the equator throughout each cycle, in accordance with Spörer's law. The shape of the distributions, when plotted for both solar hemispheres, resembles the wings of a butterfly. Related category SOLAR TOPICSAlso on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |