ACTIVE SUNSPOT RETURNS: During the late hours of April 17th, something hurled a plume of hot gas over the eastern limb of the sun. NASA's Solar Dynamics Observatory photographed the splash:
The source of this activity is probably returning sunspot AR2644. In early April the active region produced a series of M-class solar flares and shortwave radio blackouts. Now, following a two week trip around the farside of the sun, AR2644 is due to return. Amateur astronomers with solar telescopes are encouraged to monitor the sun's eastern limb for signs of the old sunspot. If it returns with any of its old potency, solar flare activity could increase sharply in the days ahead.