NASA launched a sun probe last February.  It was an important mission, purporting to help our understanding of the Sun in the same way the Hubble helped our understanding of deep space.

Some cool images (looped here) have come back from the probe.

[NOTE: If it isn't showing up, go here]

What you are seeing here is a solar flare that erupted on March 30.  These are important to understand, because such flares can cause electronic disruption on Earth.