Click on the image above for a larger .gif version.

The structure of the corona in an active region should change when a flare happens. The geometrical aspect of this has been hard to detect in the low corona, owing to the flare itself - it changes what you see. If there is a CME, of course, one can see its flows by using one wavelength or another, or by waiting until the flows get up into the coronagraphic field of view. This cartoon gives the authors' interpretation of the changes in the low corona that would be the source of flare energy. It is reasonably self-explanatory: the postflare field has the same footpoints, but has collapsed and thereby released flare energy.

10 November 2010