Physicists trace the sun's magnetic engine, 200,000 kilometers below its surface

Every eleven years, the sun's magnetic field flips. Sunspots—dark, cooler regions on the sun's surface that mark intense magnetic activity and often trigger solar eruptions—appear at mid-latitudes and migrate toward the star's equator in a butterfly-shape pattern before fading as the cycle resets. While this spectacle on the star's surface has long been visible to astronomers, where this powerful cycle begins inside the star has remained hidden until now.