Sunspots and the butterfly diagram
"sunspots do not appear at random over the surface of the sun but are concentrated in two latitude bands on either side of the equator. A butterfly diagram (figure attached below) shows the positions of the spots for each rotation of the sun since May 1874 shows that these bands first form at mid-latitudes, widen, and then move toward the equator as each cycle progresses" -https://solarscience.msfc.nasa.gov/SunspotCycle.shtml