What you’re seeing here is a solar flare (an enormous explosion of pent-up magnetic energy) coupled with a prominence (a physical eruption of gas from the surface). This event blasted something like a billion tons of material away from the Sun. Note the size of it, too: while it started from a small region on the Sun’s surface, it quickly expanded into a plume easily as big as the Sun itself! I’d estimate its size at well over a million kilometers across. It looks like most of the material fell back down to the Sun’s surface; that’s common, though sometimes such an event manages to blast the material completely away into space.