Movie Premiere

Solar Action on August 20, 2011

Two nice sunspot groups were visible on the morning of August 20th. Using a 2X Barlow lens on my Lunt 100mm h-alpha solar telescope I made the following panorama of the two groups. Notice how the magnetic fields of the sunspots disturb and change the shapes of swirling gases in their vicinity.

Sunspot 1271 on the left and sunspot 1272 on the right. (Click for full detail.)

Here's how sunspot 1271 appeared to a human eye at the telescope's eyepiece:

Sunspot 1271 (Click for full detail.)

Gases on the solar surface are constantly moving. During this observing session I attempted to make a movie of the moving gases which appear frozen in still images. I made 31 videos of sunspot 1271. Each video was about 30 seconds long containing 400 frames. I recorded one video every 60 seconds for 31 minutes before losing my nerve. Each video produced a single detailed still image made by stacking together the 200 clearest frames in the video. Tedious labor produced 31 still images, one for each minute. These 31 still images are then played in succession to produce the following movie:

31 minutes in the life of sunspot 1271 (This might take a while to load.)

The movie follows sunspot 1271 from 9:48 am to 10:19 am EDT. Motions happening over 31 minutes are shown in 3.1 seconds (in a repeating loop). In particular, notice the erupting gas plume in the lower left corner and the spouting plumes near the center!

It took four days to make this simple movie while I stumbled slowly up the learning curve. A full hour of solar action would be better, but it would have taken at least twice the time to process the resulting 60 images! I'll have to get more efficient to produce longer movies in the future.

The imperfections are fairly obvious. First, I had considerable difficulty getting the 31 images aligned. The telescope does not track perfectly, so all the still images were slightly shifted and rotated relative to each other. I had to manually align the images because I could not figure out how to get automated alignment software to do the job. You can see how the image seems to wiggle slightly as the movie plays because the alignment is not perfect. Also, in the upper right corner you can see what look like clouds jiggling over the movie. These are caused by annoying dust spots somewhere in the optical path. I'm convinced the offending dust is somewhere in the telescope and not in the camera or Barlow lens. My attempt to erase the offending dust shadows had only limited success.

Look for a sequel to the sunspot 1271 movie in a future post. I also have 30 recorded minutes of the other sunspot, 1272.