Tuesday, April 28, 2015

Telescopes Galore!

Northeast Astronomy Forum

I had a wonderful time April 18th at the Northeast Astronomy Forum (NEAF) in Suffern, NY. Similar astronomical meetings are usually on the west coast, and the majority of equipment manufacturers seem to be from western states far from my eastern Virginia home. This relatively nearby event was a great opportunity to inspect equipment first hand, speak to several experts in person, and do side by side comparisons of solar observing equipment.

More than 107 exhibitors came to the field house of Rockland Community College as shown in the imperfect panorama below.
I spent hours walking from booth to booth ogling the beautiful expensive equipment on display. I'd love to have a small dome like this in my back yard.
What to put in the dome? An excellent telescope, of course! Although I gazed on the instruments below with visceral desire, I can only dream of owning all these beautiful refractors.
If I could afford all these beauties, I might need a mount like this next one designed for telescope hoarders.
Sometimes, binoculars give the best views. For only about $3,000 I could own these magnificent 100X27.5 Lunt binoculars.
Some telescopes, like the one below, were custom made works of art.
Telescopes were not the only items on display. One exhibitor crafted beautiful equipment from wood, including this shielded laptop desk.
In another exhibit experts illustrated mirror grinding techniques.
A few vendors sold meteorites and fossils.
I bought one pretty slice of a rare pallasite meteorite from Steve Arnold, one of TV's Meteorite Men. My small extraterrestrial fragment has a beautiful green transparent oval of olivine (peridot) embedded within silvery criss-crossed iron-nickle crystals.
The sky cleared just in time for April 18th, so I had an opportunity to view the Sun through a number of instruments set up in a courtyard outside the exhibition hall.
One fascinating piece of equipment was the Shelyak spectroscope which produced a view of the solar absorption spectrum in glorious, clear, high resolution. I had seen many pictures of this spectrum, but never viewed it live through an eyepiece with my own eyes. It was an astounding sight to see dark absorption lines so brilliantly displayed against a bright rainbow background! By turning the micrometer dial, as the gentleman is doing below, I could slowly move through the entire spectrum from red to violet.
I was particularly interested in views of the Sun through the monster 152mm double stacked Lunt solar telescope pictured below.
I'm glad I had the chance to compare the 152mm with other scopes nearby. I strongly considered buying this giant scope until I saw the view it produced and listened to words of caution from expert observers. I expected the 152mm view to knock my socks off, but it wasn't better than views I get through my much less expensive 100mm scope. Instead of spending big bucks to get the 152mm, I decided to buy equipment to upgrade my 100mm. When my second Lunt etalon filter arrives, I will have a double stacked solar telescope like this one.
The best views available, in my opinion, came from the following pair of scopes.
The larger Astrophysics 6-inch refractor, on the left, equipped with a Daystar solar filter, showed a beautifully magnified prominence and spicules on the solar limb. The smaller companion double stacked Lunt 80mm scope on the right provided an astounding 3-dimensional view of the entire Sun through a binocular viewer. The binocular view was so beautiful I had to buy a binoviewer for myself later that afternoon. I'm anxious to see the image my upgraded 100mm scope will give with the binocular eyepiece. My equipment should produce equally astounding views.
I also purchased a new camera and solar guider at the show. I'll write about them in future posts.

Monday, April 20, 2015

Beautiful Day

Finally! Some Sunspots!

High thin clouds marred a perfect sky on April12th. The Sun had been mostly blank for two previous weeks, and clouds were forecast for many days in the future. So April 12th was an observing opportunity I couldn't afford to pass up. It was a beautiful day with comfortable 65 degree temperature and good seeing.

Significant sunspot group 2321 had just rotated into view around the Sun's eastern limb. The following picture is a 2-image mosaic made with a 2X Barlow lens. Sunspot group 2321 is on the left closest to the limb, and a small sunspot pair, named 2322, is near the right edge.
Small sunspots approaching the Sun's western limb were accompanied by a number of filaments. These spots would soon rotate out of view. The following 5-image mosaic shows 2323 on the left, and 2320 on the right.
These images seem a bit washed out to me. I expected sharper detail because the seeing was good. Perhaps intermittent high thin clouds caused some degradation.

Sunday, April 12, 2015

Limb Fireworks

Cool Day, Hot Sun

Breezy conditions and chilly 40 degree temperature on March 29th made observing conditions almost uncomfortable. Seeing was poor, but absolutely clear skies were hard to resist.

Although most of the Sun was blank, one good-sized sunspot and a spiky eruption on the western limb made my efforts worthwhile. The first picture below is an 8-image mosaic made with a 2X Barlow lens. It shows the solitary major sunspot, 2305, below center and a dramatic jet associated with departing sunspots shooting out from the western limb on the right.
Thirty minutes later the erupting spikes had changed as shown in the following image.
It would have been nice to make a time lapse movie of these erupting features, but I decided against this for two reasons. First, no sunspot umbra was nearby. I use a relatively stationary umbra to align video frames and correct inevitable image drift over the duration of a time lapse movie. Second, seeing was really terrible! At times the solar surface was completely blurred.

During one short period of slightly improved seeing I recorded the following solo image of sunspot 2305.
This is far from the most detailed image I've ever made, but it's not bad considering the generally poor seeing conditions during today's observing session.

Saturday, April 4, 2015


Comet Lovejoy in Cassiopeia

Since my last post I've learned how to increase the effective exposure times of my sky photos by stacking individual images. The individual photos used below were taken on March 15th when comet Lovejoy was still visible in the constellation Cassiopeia. By this time the comet was getting dimmer, its tail was diminishing, and it was getting lower in the sky. I missed a great opportunity for nice photos two months earlier. I didn't have equipment for sky tracking in January and February when the comet was bright with a long prominent tail high in the sky. Equipment was finally in hand on March 15th, so I finally had a chance to capture the fading comet.

I practiced stacking with three increasing magnifications. The first picture below is a stack of three individual 3-minute exposures with a 55mm lens. The stacking, or addition, of the images was done with a program called Deep Sky Stacker. Comet Lovejoy is the small, fuzzy, green object left of center very close to the white star Delta-Cassiopeiae (Ruchbah). No tail is visible. The "W" shape of Cassiopeia's bright stars is entirely visible. The tight grouping of stars near the lower left corner is the double cluster in the constellation Perseus. The small pink object to the lower right of the comet is star cluster NGC 457.
The next more magnified image is a stack of three individual 2-minute exposures with a 110mm lens. The green comet and white star are more clearly separated, and the comet's tail is on the threshold of visibility.
The last picture, magnified a bit more, is a stack of three individual 2-minute exposures with a 150mm lens.
I was able to achieve a uniform dark sky background in the pictures above because one of my image processing programs, Star Tools, removed brightness gradients and vignetting. The next image illustrates what the previous picture would be like without gradient removal.
Colors seem nicer in this last picture even though the center is too bright. The comet's green color looks particularly nice. I really don't know what I'm doing with color management during image processing. In the future I'd like to try stacking 9 or 10 images to better capture faint details like the comet's tail not seen in the pictures above.

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