Blundering around on NASA, I picked up on Sunspot 720 , which not only produced 5 huge solar flares, but delivered the last one in 30 minutes. From 8 light-minutes away. A bit of quick calculation reveals that the storm was thrown at over a quarter of the speed of light! Here’s a closeup of the sunspot itself: “[Coronal Mass Ejections] can account for most proton storms,” says [ RHESSI mission head Robert] Lin, but not the proton storm of January 20th [2005]. He theorises that it was channelled along the Sun’s magnetic field lines. But still... faster than 25% of c! An interesting article.
Linux Advocate in Western Australia