Prominence to Filament

3D Transition

Prominences climb above the Sun's limb like huge flames. Solar rotation will eventually bring a prominence on the eastern limb onto the Sun's disc. If the prominence lasts long enough for this to happen, it will appear as a dark, cloud-like filament hanging above the brighter background.

A few days before my observing session on August 27th a huge prominence was suspended above the Sun's northeastern limb. By the time I observed on the 27th solar rotation had brought this prominence onto the Sun's Earth-facing disc where it could be seen as the enormous elongated filament visible in the first image below. This picture is a 3-image mosaic made with a 2X Barlow lens showing the three-dimensional transition from prominence to filament. Only a small portion of the filament still remains as a limb prominence seen against black background. Solar rotation from east to west is from left to right in the image. It's easy to see how the diagonal, elongated filament was once near the limb a few days before.

The next picture is a 26-image mosaic showing the entire solar disc on August 27th. Some nice, nearly vertical filaments are present as well as four sunspots. (Click on the image for a larger view.)

Filaments float nicely in this inverted image.

Next is a closer view of the sunspot triangle near disc center. Sunspot 2149 is on top with sunspot 2151 (left) and sunspot 2150 (right) below. This is a 9-image mosaic showing good detail.

Remaining sunspot 2148 was approaching the western limb. It rotated out of sight two days later.

Seeing was reasonably good on the 27th, so I decided to construct a time lapse video of sunspot 2149. I'm still processing the images and will try to feature the movie in my next post.

Resting Sun

Few Features

The Sun has been napping for the past two weeks, showing no big sunspots or dramatically long filaments. It was also cloudy for two weeks, so, when the sky finally cleared on August 14th, even though solar features were sparse, I decided to set up my telescope and get some images. The temperature was mild for this time of year. Observing was relatively comfortable just before noon, but the seeing was only mediocre. I worked for only about one hour.

Large featureless areas in the Sun's western half can be seen in the following 6-image mosaic made with a 2X Barlow lens. Modest sunspot 2138 is in the upper right while a white hot spot and two filaments are visible near the bottom.

A closer look at sunspot 2138 reveals a single umbra and simple surrounding structure.

The white hot spot, seen in the next image near two filaments, became a small sunspot a day or two after this picture was recorded.

On the Sun's eastern side complex sunspot group 2139 stretched out from the small black umbra seen on the right below to the white area immediately to the left of the umbra. Notice the almost circular white hot spot on the far left near the limb. There, white emission is seen behind some overhead parallel horizontal streaks giving a 3-dimensional effect. Movies taken at the same time as my observation showed this feature churning rapidly. A day or two later this hot spot became a sunspot.

Just north of the scene shown in the previous image some nice prominences were on display.

A few other prominences were also present.

The Sun will eventually wake from its nap. I look forward to working in cooler temperatures as autumn approaches. 

Black Widow

Another Bad Bug

A few days ago we came upon this nasty spider resting in its web on the foundation of our house. The horizontal blue lines are 2 cm apart, about 3/4 inch.

I'm beginning regular bug inspections armed with insecticide.