Cassiopeia Observatory

Sun Active Region 1339
Posted: 9 November 2011

The sky was clear mid-day on Tuesday, 8 November, so I decided to open the observatory for some solar observing. By the time I opened the observatory at 1148 MST, temperature 64°F, there were some cirrus clouds approaching from the west. Fortunately, they did not interfere with my observing, although the seeing was not very good. I attached my new Orion full-aperture solar filter to the 8" LX200-ACF and did some observing of the sun at 77X. Although the seeing was not very steady, the view was sharp for brief moments. I added the 3X TeleXtender (yielding 231X) and occasionally got a clear view of the large sunspot known as "Active Region 1339", which is the largest sunspot in three decades.

I then attached the iPhone 4 to the 8" telescope using the Magnilux MX-1 afocal adapter and did some afocal imaging at 77X and 231X. The poor seeing really made imaging with the iPhone difficult. But I managed a couple of reasonable images. Both are slightly cropped from the full-frame photos, and are at 77X and 231X respectively. Several other sunspots are visible in the top image.

I swapped the iPhone for the D7000 DSLR and did some prime focus imaging, with this full-frame result, 1/640sec, ISO 500:

This is a slightly cropped image, prime focus + 3X TeleXtender, 1/1000sec, ISO 1000:

The seeing was so bad that focusing the sun in the camera viewfinder was very difficult. I ended imaging at 1245 MST and took a final look at the sun at 77X.

I had hoped to re-open the observatory after sunset to observe the asteroid 2005 YU55, which had made its closest approach to Earth about an hour before local sunset. However, clouds were moving in as sunset approached and covered much of the sky after twilight ended. I'll have to wait for the next near-miss asteroid.

On my previous report, I included a video I made of the ISS Moon transit. For those using Firefox and can not get the video to load, or if you want to view the full-size HD video, I have made it available here:

I have written a short article on "Some Thoughts on Light Pollution and Light Nuisance". Feel free to read it and pass the link (http://www.weasner.com/etx/lp/lp_thoughts.html) on to others if you are so inclined.