The Great Flares of October, 2003

If this simply is not the most fasacinating picture of the Sun, and one that completely awes you as you move through this course, then I cannot imagine what might interest you more. The end of October, 2003 saw a series of events unlike anything witnessed by solar scientists in recorded history. On October 20, a large sunspot group appeared on the western limb of the Sun and slowly rotated into view. A few days later, a second large spot joined the first, and the Sun suddenly had two spots both of which exceeded the diameter of planet Jupiter. These large sunspots unleashed a series of X-class flares shortly after their appearance, but since their coronal mass ejections were not directly aimed at the Earth, there was little to fear. Then on the morning of October 28, the spot depicted in the background image to the left of center erupted an X-17 flare aimed directly at Earth. The following morning, another flare of X-10 class erupted from the same region and followed close behind the first. The evenings of October 29 and October 30 saw spectacular aurora as far south as California and Florida. Alas, it was cloudy in Minnesota for that entire week, but the images collected from the SpaceWeather.com website show what people living outside of Minnesota saw those evenings.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This image of the Sun was taken by the SOHO space satellite on October 26, 2003 and shows the high photosphere activity associated with the pair of giant sunspots. Notice the spectacular solar prominence to the left of this picture. This prominence reached an altitude of 30 Earths above the Sun.

 

 

 

Below is an image set of the Sun over a period of 2 weeks, commencing on October 20. From left to right in row one are images from October 20, 23, and 26. In row two are images from October 27, 28, and 29. Row three contains images from October 30, 31, and November 1. The bottom and fourth row shows the Sun as it appeared on November 2, 3, and 4. Remember, it is the rotation of the Sun that causes the spots to appear to be moving from left to right, and not the actual motion of sunspots themselves.

 

 

 

 

Even more incredible than these solar images are photpgraphs taken by Astronomers on the evenings of October 29 and 30 when the coronal mass ejections from the flares of October 28 and 29 struck the Earth's magnetosphere.

 

Okay ... so just what happened to cause all of this incredible activity?

On the morning of Tuesday, October 27, Sunspot group 486 was facing the Earth when a region ripped open and a tremendous outpouring of solar material erupted in a spectacular X 17.2 class flare whose Coronal Mass Ejection was aimed directly at the Earth. The sequential images shown below are from the SOHO space satellite and show the bright flare as it appeared to the instrument's camera. Just 36 hours later, the same sunspot region erupted again, unleashing an X 10.0 class solar flare. Both fast moving CME's struck the Earth during the nights of October 28 and 29 producing the fantastic auroral displays shown above. Click on the image below ... upper left picture of the sextet to see a video of the Sun during late October and early November of 2003 when this event happened.

The pair of pictures below show the Sun as it appears in a Hydrogen Alpha filter that allows astronomers to get a more detailed look at the photosphere. Notice the bright regions associated with the sunspot groups.

 

 

The image below shows the extent of the Northern Light at 11:03 PM CST.

 

Finally, I have included a nice close-up photograph of sunspot group 486, taken the day after the two giant flares. Interestingly, at 7:50 CST on the morning of November 4, this same group erupted in the largest solar flare ever recorded. The solar satellite that records these activities was overwhelmed and all shortwave radio communications were blacked out shortly thereafter over the entire upper half of the sunlit northern hemisphere. Fortunately, this sunspot group was on the far eastern limb of the Sun and the CME was directed in a direction away from the Earth.

 

 

 

 

 

Return to Solar Features and Events or to the Sun Introduction, or to the Syllabus.


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