The Sun’s Recent Behavior Is Odd, Scientists Baffled

Sunspots, markers of magnetic activity on the sun’s surface, provide a visual proxy to mark the cycle’s evolution, appearing in droves at maximum and all but disappearing at minimum. But the behavior of our host star is not as predictable as all that—the most recent solar minimum was surprisingly deep and long, finally bottoming out around late 2008 or so.

From 1995 to 2007, the frequency shifts in the oscillations had matched up well with the sunspot counts. And at shallower depths within the sun, the seismic and sunspot activity were in phase for the most recent solar minimum as well. All in all, the cycle was definitely unusual…

Scientific American