Solar Flare 20070516
Sunspot 956
Subtraction image to show extent of flare tsunami, 171Å, not in 3D
Type A subtraction. 1841 hours subtracted from 1716 hours. Not in 3d
Flare strength: GOES class C2.9
The brown zones are active areas on the sun. The lighter, cyan zone is the area penetrated by the solar tsunami (flare shock wave). Other cyan areas have also changed (blinkers etc) but the shock wave is extensive and distinctive.
This is the same subtraction method I used for the 20070505 flare.
Red/cyan anaglyph: movie, 171 Å
Use red/cyan 3D glasses 
and wait for the movie to load.
The local eruption penetrates into the areas shown on the subtraction image.
195 Ångstrom anaglyph stereoscopic movie
Use red/cyan goggles and wait for the movie to load.
NB: Gif movie rendition in Internet Explorer for Mac is useless, but IE for Windows is good.
Works well in Safari and Opera (Mac) but not quite right in Firefox for Windows.
- Bright ribbon flare. (Seen as a double line to the right and above the active region for a brief period).
- Post-flare loops: they look like a bright slinky toy or spiral on the last frame.
- Dark flare "local shock wave". Judging by a subsequent H alpha image, this was a filament eruption.
- Solar flare lighter shock wave. Much faster and fainter. This shock travels to the right and is only visible on 5 frames as a curved wave-front. This an EIT wave.
Subtraction movie, 195Å, not in 3D
The sequential 195Å images, taken every 5 minutes, have been subtracted from each other (type A), then combined into a gif movie. This makes it much easier to see the shock wave generated by the flare.
- The wave travels to the right, but not to the left. Since the edge of the solar disc is so close to the left (East), a shock wave there might be harder to see. So it is not behaving like a concentric ripple on a pond. Moreton waves lower down in the chromosphere often behave like ripples but are seen in H alpha.
- The wave does not extend over the whole solar disc, but fades out.
Type C subtraction, contrast enhanced, just one frame of the movie.
C subtraction, invented by the author, is much prettier than standard A subtraction, or my B version, so may become more common on this web site!
Full disc 304Å at the time of this flare (big file). The EIT wave does not show up at 304Å .
A thin filament shows up on the 304Å image, between the flaring sunspot and the "continually changing dark area," which is a coronal hole .
Links
STEREO mission anaglyph for this day shows the coronal hole.
Contrast enhanced version by the author
NASA 3D movie for 2007 05 16
NASA 3D movie in 304Å showing active sun from 12-16 May
The Hi1 camera revealed a Coronal Mass Ejection before and during this flare.
(I have not managed to detect how the CME came from this flare, or indeed if they were truly related. More work needed on the STEREO images around this time!)
Harrison investigation of flare/CME relationship.
H alpha image by Emiel Veldhuis two days later showed the reformed filament that erupted during the flare.
(This is common behaviour for sunspot-related filaments. Filaments form in the separation zone between magnetic fields of opposite polarity. Flares do not disrupt this magnetic arrangement and so it is all ready for another filament.)