Important notice about STEREO Behind
X2 Flare and CME
The Sun blasted out an X2 flare (X flares are the brightest in soft X-rays) and it also unleashed a substantial coronal mass ejection that started late on Sept. 7, 2011. From its perspective about 90 degrees ahead of Earth, the STEREO Ahead spacecraft observed a bright flash of a flare and erupting cloud that appeared to be heading in the general direction of Earth. And several days later instruments showed that Earth was hit by the magnetic energy in the CME cloud, causing auroras to be seen as far south as Vermont and Michigan. The video clip covers about 15 hours of activity and was taken in extreme UV light. Also, towards the end of the clip a prominence becomes unstable and rises up above the solar surface.
Last Revised: March 19, 2018 15:00:39 UTC
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