Surf the Wave (November 4, 2004)
Hi-res TIF image (2.5M).
On Nov. 3, 2004 two M-class or moderate solar flares erupted from
Active Region 696. What is unusual about these events is that the
magnetic instability that led to them also triggered pulses that swept
across a substantial area of the Sun's surface. This motion, like a
tidal wave, is called a Moreton wave, a relatively rare event. Though
the waves are somewhat subtle, they can be observed about 3/4 of the way
through the extreme ultraviolet movie from SOHO as it expands across
the upper portion of the Sun. To generate enough force to travel such
distances of hundreds of thousands of miles across the surface of the
Sun --- and hundreds of millions of km the associated coronal mass
ejection travels across the solar system --- suggests the enormous
magnetic energy release that triggers such a storm in the first place.
The movie shows just the one day.
SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.
If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to email@example.com.