A large sunspot was captured by NASA’s STEREO instrument marking what could be the end of the longest solar minimum in the last hundred years. Sunspot activity and the solar flares that are generated go through an 11-year cycle. For some unknown reason, this most recent solar minimum has lasted longer than normal.
For more see “Big Solar Flare Portends Sun’s Return to Normal” from Wired Science
The Physical Environment textbook link: “The Sun“