The Sun Acts Up

Philip C. Steffey, Ph.D.


The Sun became surprisingly active in late October, 2003, three years after its last activity maximum.  On the 22nd a huge sunspot group named Active Region 10484 produced a flare and subsequent coronal mass ejection toward Earth.  On the 24th, several B-CC faculty and staff members and students viewed the spot group and others in white light with the 14-inch telescope.  Recording equipment was unavailable, but one viewer videotaped the Sun with a smaller telescope, which showed the whole disc, on the 25th and 27th, when another spot group became active (AR 10486).  See the still pictures below.  On the 28th, the latter produced one of the most powerful flares and cmeÕs ever recorded, but cloudiness prevented observation in Daytona Beach.  Full-disc and higher resolution video images were obtained on the 29th, when the elliptical ring-shaped spot group north of AR10486 (AR10488) had developed the largest single spot yet in the activity period.  Both groups could be seen with the naked eye--using an appropriately dense filter.

Fortunately, the speedy cloud of heavy, charged particles released in the cme of Oct. 22 caused no important disturbance of terrestrial telecommunication or electric power systems.  The event of Oct. 28 produced minor disturbances of commercial aircraft communications and bright aurora borealis displays visible, in dark skies, as far south as latitude +34 degrees or so, just 20 hours later.


                  

 

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