This is the top portion of the 22 degree solar halo caused by high altitude ice crystals. This was in the morning, so I had great difficulty screening out the sun as I was limited to my backward for this one.
The motion of the "rainbow" is due to the fact that the halo track the motion of the sun.
Note that ths curve of the "rainbow" portion is downward. This differentiates this from a circumzenithal arc ( CZA ) which opens upward and is centered on the zenith rather than the sun itself.
A CZA is formed by flat ice crystals arranged so that the sunlight enters one facet and leaves though the opposite side . The halo works more like traditional rainbow. The normal 22 degree halo can be either a bright ring, or in this case colored by dispersion.
This series was deflickered, cropped from the original 3MP shots from the F30 down to a 16:9 aspect frame and resampled down to 720p frames. In addition SBG was to adjust the curves over the series to compensate for the F30 rather lack luster dynamic range. There was also a lot of glare, as we were shooting into the sun. So dropping out the bottom and top helped make the clip pop a bit better.
Remember, we are talking a $200 P&S being used to generate this series. Which is quite acceptable.