Sunspot Constellation

Beautiful Morning Conditions

Sunspot activity has been very slowly increasing. On April 26th it was five months since my last solar imaging session. A completely cloud free morning and well placed sunspots enticed me outside to set up my solar telescope. The air was very dry with temperatures in the mid 50's. A steady wind blew with occasional puffy gusts. Only one minor annoyance was present - every surface on my patio was covered with swarms of tiny red clover mites! These I had to brush off from equipment cases when the session ended.

The following imperfect 15-panel full disc mosaic shows five individual sunspot umbras grouped in the southern hemisphere along with a couple of unimpressive filaments. An unfortunate bright streak runs across the center diameter because software combining the 15 constituent images could not properly blend brightness differences. Also, no prominences or spicules are visible around the rim because camera settings made capture of these relatively dim features impossible.

The next 6-panel mosaic avoids the previous mosaic's blending problem and captures most of the interesting southern hemisphere features. (Click on the images for a larger view.)

During this imaging session video downloads were extremely rapid! I used a powered USB hub with my newest laptop where videos were downloaded onto a solid state drive. The next image is a stack of 400 frames from a 4,000-frame video. It took only 60 seconds to capture the 4,000-frame video. That's an amazing 66.7 frames/sec! Seeing conditions were also good during this time, so the image below is probably the finest resolution my system can achieve. (Lunt 100mm solar telescope, 3X Barlow lens, ZWOASI174MM camera.) I also used a Hinode solar guider to minimize any drift due to imperfect tracking during video capture. Once again, click on the image to see the full detail.

While viewing this sunspot grouping for a few hours it occurred to me that it resembled the constellation, Cassiopeia. Actually, the sunspots are a horizontally flipped version of Cassiopeia as you can see from the constellation and flipped image below.

When I first began observing I saw a small flare erupt within the sunspot group. The next 4-frame animation shows the flare evolve over about 6.5 minutes of activity. It would have been nice to capture more of the eruption, but I wasn't prepared, and my solar guider had not yet been installed.

I was a bit out of practice with good imaging technique after 5 months off. There might have been a light leak somewhere in my system that flat fielding did not remove. I need to rediscover correct camera settings to capture limb prominences.