In February 2011, a sunspot group numbered 1158 blasted out a big flare, the first that was aimed at us here on Earth during the current colar cycle. It wasn't a big flare as they go, nor did it do any harm here, but it was still pretty impressive. This image in the far ultraviolet shows the looping magnetic field lines of the Sun and the bright flare leaping from them.
Credit: NASA/SDO
Original blog post
Credit: NASA/SDO
Original blog post
