Hydrogen-alpha image of a solar flare.

The small sunspot observed close to the limb on October 24th 2003 was part of the big active region that produced the X17.2 flare on October 28th. The movie shows a super-penumbral loop system eruption. It appears that the footpoints of the loops, as well as some loop tops, become bright during the flare. The data indicate that the flare was triggered by new flux emerging in the lower right corner of the image. This particular image is from near the end of the flare. Tick marks are one arc second apart. Structure on spatial scales of 0.2 arc seconds is visible in this image. Pictures from the Dunn Solar Telescope at the Sacramento Peak Observatory.See the December 2003 NOAO Newsletter (currently only available in PDF format).