Solar Limb Action
Solar activity is increasing slightly quicker than expected. On October 2nd observing conditions were too good to pass up. Not even one cloud appeared in the blue sky, and the temperature hovered near 70 degrees. During the first look through the eyepiece of my solar telescope I was surprised to see one of the largest, brightest prominences I've ever observed! It arched high above the limb as you can see in the first image below.
Solar Activity
Light pollution from neighboring houses makes telescopic observing at night from my back yard nearly impossible. An additional obstacle has recently appeared. Milky white haze from western wildfire smoke blankets the sky. Each night I try using a telescope I'm reminded of why I decided to do solar observing during the day.
During morning daylight on September 10th haze and neighboring spotlights still(!) shining into my yard had no effect on the Sun! Conditions were excellent, with only a few small widely scattered clouds, a gentle puffing breeze, and temperatures ranging from 66 to 71 degrees. Three days earlier solar features were more impressive and well placed. By the time I could observe on the 10th, solar rotation had carried some sunspots around the western limb out of view. A large, complex sunspot group was still visible, however, along with other interesting features.
All sunspots were located in the western solar hemisphere as can be seen in the following 11-panel mosaic. (Click on images for larger views.)
The previous image shows no rim spicules or prominences because it was processed to show disk detail. The next image overexposes the disk but shows nice features on the rim.
All previous images were made by recording almost perfectly monochromatic red light with a wavelength of 656.28 nanometers. This particular red color is emitted by excited hydrogen atoms in the Sun's chromosphere. I tune the filter in my solar telescope to specifically transmit only this one wavelength. So the previous images show what hydrogen gas is doing in the layer of the Sun where the temperature and density have the right values to produce this particular excitation in hydrogen.
If I tune the filter so it transmits some other wavelength besides exactly 656.28 nanometers, the light my camera records will no longer come mostly from excited hydrogen. Instead, the camera will record red light capable of leaving the Sun from any thermally emitting solar material. In fact, the camera will record red light coming from the solar photosphere, the layer beneath the chromosphere. The photosphere emits a continuous spectrum of all colors which appears yellowish-white to our eyes. When the filter is tuned away from the 656.28 nanometer wavelength, the camera will record a red portion of this overall continuous solar spectrum.
The next image shows how the sunspots look when the filter is tuned away from 656.28 nanometers. Notice how many different umbras are visible, including several small ones in the lower active area. It's really a complicated arrangement of umbras! Notice also the mottled appearance of the solar disk not occupied by sunspots. This is caused by unresolved solar granules - columns of rising and falling gas in the photosphere. Unfortunately, some dark vertical stripes appear in the image which could not be removed because I failed to take a flat field for this image.
Although there were no impressive features in the Sun's eastern hemisphere, there was one interesting small prominence appearing in the last image below. Notice how this prominence is blending into a faint filament as the Sun rotates.
Lucky Timing
On July 3rd it had been more than two months since my last solar imaging session. Conditions were unusually nice for a July morning! Humidity was low, skies were clear, a modest breeze blew away annoying insects, and temperature ranged in the low 70's. Summer mornings in Williamsburg are rarely clear and clouds inevitably increase near noon. By 11:00 AM clouds put an end to my observing opportunity. The satellite view below shows the temporary clear viewing window for southeastern Virginia.
One major sunspot and a few filaments appeared on the Sun's disc as you can see in the next full-disc mosaic constructed from 21 individual panels.
The previous mosaic was processed to show details on the disc so rim details are not visible. The next mosaic was processed to show prominences and spicules around the rim.
When the previous disc mosaic is inverted positive to negative, the floating nature of the filaments becomes more apparent. Once again, you should enlarge these images to see the best detail.
Outer Banks 2021
Our annual trip to the North Carolina shore was a week later than last year. Traffic was incredibly heavy on Route 12 as we neared our rented house. It took 50 minutes to cover the final 2.5 miles! Cars, frozen in place, stretched as far as we could see. Some enterprising kids were selling frozen ice pops and handing them through car windows as traffic crawled by.
Eventually, we did leave the traffic backup and arrived at our house pictured below. A flag flies from the crow's nest.
There was also a screened porch with comfortable chairs and a nice swing. This was a great place for reading in the swing chair, napping, eating breakfast, or hearing wind brushing through pine branches outside.
Sophie couldn't wait to jump in.
The pool was nice, but much more time was spent at the beach.
Paddle boarding was difficult this year because windy conditions made rough water. After a day packed with activities in the sun youngsters sometimes needed a break inside. 
One evening there was a display of crepuscular and anticrepuscular rays. The first picture shows crepuscular rays looking northwest. The second picture, a few seconds later, shows anticrepuscular rays converging on the antisolar point exactly 180 degrees to the southeast. 
It was pleasantly breezy up in the crow's nest when these family pictures were taken.
Too Many Clouds!
The remote arctic annular solar eclipse totality path of June 10 passed near the North Pole and into northern Canada. The only viewing possibility at my Virginia location was a partial eclipse for a short time near dawn. Unfortunately, clouds hid the Sun. This satellite view shows cloudy conditions in the eastern US at about 6:36 am EDT. The red dot marks my location. Notice some clear sky along the New Jersey shore and parts of Delaware and Maryland. Viewers there took some nice pictures of a rising crescent Sun. In my corner of Virginia, however, no luck.
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.
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.
