A cloud of ionized gas floats over the surface of the sun, in this mind-blowing photo by Alan Friedman. Using a filter that only records a narrow wavelength of light emitted by hydrogen, Friedman captured the sun's texture... and eruption.

According to Phil Plait at Bad Astronomy, that cloud of ionized gas, or plasma, is caused by an erupting sunspot. The plasma follows the sun's magnetic fields as it flies outwards, and either returns to the sun or goes out into space. Click the link for the bigger version of the image.
[Alan Friedman via The Week]