Monday, April 21, 2014

Morning Session

Better Seeing

During the past few years I've noticed solar observing conditions are best in the morning between 8am and 11am. The atmosphere seems steadier then, before significant daytime heating occurs. On April 10th I was able to set up equipment for a morning session and, for the first time at my new site, there was almost no wind. I began recording at 8:44am EDT. Seeing was about 7/10 compared to the 5/10 conditions present on previous afternoon sessions. Unfortunately, I had some trouble with mount alignment which caused poor tracking later in the session. Also, for some unknown reason, my DMK41 camera had poor communication with its controlling computer causing video capture times to be twice as long as normal. Consequently, tracking and communication problems cancelled some of the advantages of good seeing.

Most of the interesting solar features were near the east limb. The following mosaic, made with a 2X Barlow lens, is a combination of 10 individual images. The three-umbra sunspot group 2032 can be seen in the upper right. Some nice prominences decorate the limb. A few dark filaments are scattered about. Details are fairly good because the atmosphere was relatively steady. (Click on the images below for enlarged views.)
Next is a closer look at sunspot group 2032. A white burst of energy is located just to the right of the tallest prominence.
The next image is a magnified view of the sunspots made with a 5X Barlow lens. At high magnification the sunspots were slowly drifting due to poor tracking while the video was recorded. In spite of poor tracking there is a good amount of detail in the picture.
The only other sunspot, 2030, was located near the western limb as shown below.
Episodes of good seeing allowed fine details to be visible in this picture of swirling spicules on the Sun's disc.
Finally, an arching prominence was present on the southwestern limb.
I'll have to work on mount alignment and camera communication problems in my next observing session.

Sunday, April 13, 2014

Erupting Prominence

Surprise Explosion!

A warm afternoon of solar observing preceded the nighttime session I wrote about in my previous post. The April 2nd afternoon Sun displayed a nice variety of sunspots and filaments, but seeing was not very good. Consequently, the images below aren't as sharp as I'd like. I'm still waiting for a day with good seeing. Maybe morning sessions will have steadier air than afternoons.

The first image below is an imperfect mosaic of 18 individual images taken with a 2X Barlow lens. At top left are sunspots 2027 and 2022. Below them on the left are sunspots 2028 and 2026. Large sunspot group 2021 is just below center to the right. Some nice filaments stretch over the right half of the Sun. The lower left portion of the image is missing because I sometimes lose track of where I am on the disc while moving the telescope to capture patches of the Sun's surface.
My goal for the day was to test a newly acquired tilt adjuster to see if it would eliminate circular interference fringes which have plagued magnified images made with my 5X Barlow lens. The fringes were there as usual before I placed the tilt adjuster into the optical path. When I finished installing the adjuster, the fringes were gone! It worked! I was pleasantly surprised! Below are three magnified images made with the 5X Barlow lens. Details are not particularly sharp, but there are no interference fringes.

First is sunspot 2022 showing a parade of dark arches between the large spot and its small companion.
Next is sunspot 2027 whose dark umbra is split by a curved white energetic feature. More intense white emissions pour from under a dark arching filament in the region to the left of the spot.
Finally, the three-umbra sunspot group 2021 sits in the midst of swirling spicules.
Eventually, just by chance, I'll be lucky to observe in good seeing. When that happens I'm curious to see how much more detail I can capture with the 5X Barlow lens.

After imaging the features on the solar disc I roamed around the rim looking for interesting prominences. That's when I came upon an erupting prominence! Below are two images captured shortly after the eruption began.
The erupting prominence is the tall feature emerging nearly perpendicular to the solar rim. The previous images were taken just two minutes after I first noticed the explosion.

Usually, prominences move rather slowly. This eruption was the first time I've ever seen motion rapid enough to be noticed in just a minute or so. When I first brought the eruption into the field of view it was a small bright lump. A minute later the bright lump had grown significantly outward, and I said, "Whoa!"

Below is a movie showing 11 minutes of action beginning with a bright lump at 3:12:36 EDT and ending with rapidly dimming outward movement at 3:23:19 EDT. I made twenty, 200-frame videos - one every 30 seconds for roughly 11 minutes. The twenty videos resulted in twenty still frames which make up the movie.
The solar surface on the left wavers and goes in and out of focus as the movie plays because the seeing was changing over the movie's duration.  

Saturday, April 5, 2014

Old Telescope

Nighttime Observing

In 1975 I bought my first telescope, a Celestron 8-inch Schmidt-Cassegrain. Over the years I've used it many times and learned lots about observing and telescope operation. Recently, however, I haven't used it much because its old fork mount is so hard to use compared to newer computer controlled mounts.

A few weeks ago I purchased adapters to attach the aged Celestron to my beautiful Paramount MX mount. On April 2nd, after a full afternoon of solar imaging with a hydrogen-alpha solar telescope, I used the Celestron to image sunspots through a mylar filter. These sunspot images were poor, but the sky was clear and the weather mild. So I decided to leave the equipment outside and wait for darkness.

The evening session began with a quick look at some familiar celestial sights through an ordinary eyepiece. Then I decided to image Jupiter and the Moon. I attached my DMK41 video camera at the Celestron's prime focus and focused with difficulty on Jupiter. Over the years the Celestron focus has been soft, and this night was no exception. The Jupiter image below was produced by capturing 2,000 video frames, aligning them in Registax 6, stacking the best 100 frames, and then sharpening the final image using wavelets in Registax 6. I have no color filters, so the image is monochrome.

Although seeing was mediocre, some details on Jupiter are barely visible. For example, there are hints of circular features just below the equator. Three moons are visible. From left to right they are: Europa, Io, and Ganymede. The fourth moon, Callisto, was out of view off to the right. Some details reach the threshold of visibility, but are nowhere near the resolution achieved by experts in planetary imaging.
I also captured 7 pictures of the crescent Moon and combined them in the following 7-image mosaic. A slight pale blue color has been added. (Click on the image for a larger view.)
Sunspot images with the Celestron were very disappointing, but hydrogen-alpha solar pictures from the afternoon of April 2nd were much better. I'll post them in my next blog.

People say I'm crazy doing what I'm doing
Well they give me all kinds of warnings to save me from ruin
When I say that I'm o.k. well they look at me kind of strange
Surely you're not happy now you no longer play the game

People say I'm lazy dreaming my life away
Well they give me all kinds of advice designed to enlighten me
When I tell them that I'm doing fine watching shadows on the wall
Don't you miss the big time boy you're no longer on the ball

I'm just sitting here watching the wheels go round and round
I really love to watch them roll
No longer riding on the merry-go-round
I just had to let it go

John Lennon