Tag telescopes

Another eclipse in the books

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A stack of images taken two minutes after the eclipse peaked (delayed due to cloud cover) illustrates the approximate 96 percent eclipse. The brightest area at top is direct sunlight, the gray area beneath it is penumbral shadow, with transition to the coppery-colored umbral shadow where no direct sunlight reaches the lunar surface.

The August 27 – 28 partial lunar eclipse was enjoyable to watch but presented some challenges to photograph. Before nightfall, we set up a modestly sized telescope, the Askar 103APO, outside the observatory. The scope has a shorter focal length, less magnification, which would allow its camera to record the entire disk of Moon during the eclipse. The large observatory telescope, with nearly twice the focal length, would show less of the lunar disk because of its higher magnification. This outdoor setup seemed like a good idea and it was, in principle. But Moon and nearby trees presented our first challenge of the night.

Trees blocked the view from the observatory so a telescope was set up in a more hospitable site. A 100-foot extension cord allowed utility power to run the telescope mount. A blue lens flare is visible above the bright dot that is Moon.

Moonrise was at 8:01 PM EDT and its altitude from the horizon was going to be fairly low. The mature neighboring trees are quite tall and wide. The combination was not good and, as Moon climbed higher and eclipse time approached, time was running out. From the vantage point of the telescope outside the observatory, Moon would be behind the trees during the entire first half of the event. We had to move it.

Scouting out a new location that allowed a clear view of the sky, we located one near enough to facilities to connect to utility electric power. In darkness we moved the imaging setup.

The dark umbra of Earth’s shadow was already taking a substantial bite out of the night’s full Moon as we finished setup at the new location. We were impressed at how well our old (ca. July 2005) Meade LXD75 mount performed, tracking accurately with minimal alignment; it was a real champ! One camera automation accessory did not function as expected so we removed it and ran the Canon EOS 7D Mk. 2 camera manually. Things went well from that point on with an unobstructed view of a clear sky and a darkening Moon. The night was quiet and mild, not even a jacket was necessary, as we gazed at the dimming Moon and listened to night sounds.

This was to be a partial eclipse, meaning not all of the lunar disk would be within the deep umbra — a bright sliver of sunlight would be seen at one edge, while the opposite side of the disk would be dark, and hopefully colorful. Peak coverage was to be reached at 12:13 AM EDT. It was about 20 minutes before peak when we spotted it: a bank of clouds drifting in from the north, illuminated by ground-based light pollution, headed in to spoil the night!

A bank of clouds approached the eclipsing Moon as the hour of peak eclipse neared. A lens flare is visible to the lower right of the bright lunar dot, and a view stars can be seen in the sky.

That is how it goes, sometimes. Clouds, missteps, or mishaps spoil an otherwise exciting occasion. It doesn’t help to curse the clouds but that did not help to stop the whispered oaths! Happily, gaps were present in the cloudy mess, clear sky visible through them, hopefully allowing peeks at the eclipse. The clouds arrived, mostly blocking but indeed occasionally teasing glimpses at the then fully-developed event. We made images from about two minutes before the peak, and images from about two minutes after, but nothing from the peak moment.

Peak eclipse, at 12:13 AM EDT. Very, very eclipsed as the clouds obscured the view. Gaps in the cloud cover allowed images to be made before and after the astronomical peak coverage was reached.

An extended period of clarity followed, as the cloud bank continued on its southbound journey. We shot more images of the eclipsed Moon, rapidly changing exposure settings, seeking to record a wide range of graphic data against future processing efforts before the scene changed much. Imaging done, we took one last look, parked the telescope, then stowed and secured gear for the night. It was late and we had daytime promises to keep.

So that was another lunar eclipse in the books. There was frustration, to be sure, but there were rewards. There won’t be another lunar eclipse visible here until January 12, 2028 (a weak partial eclipse), with the next total lunar eclipse on June 26, 2029. One has the opportunity to see just so many eclipses in their lifetime, so we try and see every one we can!

P.S. At 12:30 AM, the diminishing eclipse became visible from the spot where we first set up the small telescope. And the sky was clear.

First Light: A new telescope means a new beginning

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First light image of Messier 57: The Ring Nebula. For the occasion, only 60 light frames and 30 dark frames, 15 seconds each frame, were captured and stacked. Affinity Photo 2 was used to create the stack and Pixelmator Pro for editing. M57 is a planetary nebula in constellation Lyra and was formed during the death throes of a Sun-like star.

We had been considering what our next step might be in outfitting the observatory with a more-or-less permanently mounted telescope. Would a very long focal length Cassegrain suit our needs? Both the C11 SCT and the Vixen Modified Cassegrain were available, already on hand but both had issues. After struggling with collimation on both telescopes, we were leaning toward a high-quality refractor as the solution. Long focal length on a refractor, though, means a long tube and we have limited space. The incident that damaged the Vixen pretty much forced our hand. Frustrated with collimation issues, and telescope repairs we doubt we could perform, we made the decision to go with a new refractor.

What ultimately steered us toward Askar and helped ease some (not all) doubt concerning focal lengths was the wonderfully high quality image of the “daytime Moon” we had captured with the smaller Askar 103APO — images with that level of quality can be cropped to make up for some lack of focal length. Watching YouTube reviews of some Askar’s bigger telescopes offered further assurance we were headed in the right direction.

The new Askar 151PHQ telescope installed on the observatory’s pier. At the eyepiece end is a ZWO ASIAir Plus computer and ZWO Automatic Electronic Focuser. We anticipate moving the computer to a different location on the telescope as cable management becomes a priority.

Inside doubled shipping boxes, the telescope was delivered in a solid transport case, packed in form-fit dense foam padding. The case is very high quality, very heavy, and bears multiple hand grips; it will now be set aside, stored some place against the day the telescope is taken out of service for some reason. If the case was an optional item, in our case we aren’t sure we would want it.

The Askar 151PHQ is doubtless the highest-quality telescope we have ever owned or used. It is a quadruplet astrograph, featuring a 151mm (six inch) aperture and a 1057mm focal length for an f/7 focal ratio, and designed to produce flat field images without add-on optics.

Taking advantage of a rare, relatively clear night, we went for first light using the big instrument with minimal configuration: no finder scope, no automatic tracking, no camera cooling, etc. While we had installed the ZWO AEF purchased years ago, and the ASI AirPlus, we used them only for manual electric focusing which, by the way, was a big improvement in itself! The optional hand controller was a wonderful thing to have, allowing us to watch through the eyepiece or on the computer screen and make smooth, minute adjustments to focus without telescope vibration. Yes, wonderful!

Under Bortle 6/7 skies pinpoint stars shown brightly through the eyepiece as we focused on Arcturus, then searched for M57. Our hazy skies, made worse by light pollution (maybe a Bortle 8 night), didn’t make things easy but with a little patience, a tiny, ghostly ring appeared in the field of view. We swapped out the eyepiece for the one-shot color camera, refocused, and began the imaging run. While we have much to learn about processing deep sky objects, we were happy to see the quality of the resulting stacked image: round stars and lots of them (many more stars than we’re used to seeing there), good detail in the ring, and decent color — all in 60 light, and 30 dark 15-second frames. The Moon eluded us that night, still down in the trees at midnight, but we tried solar first light the next morning.

First images of our Sun via the Askar 151PHQ were recorded under poor seeing conditions but, with some work, produced some pretty impressive results. A TeleVue Powermate 2.5X Barlow was employed here. We hope to refine our setup for the new telescope for better edge-to-edge focus. The telescope was equipped with a Baader white light solar film filter and monochrome camera; false color applied during processing.

Placing a Baader Solar film filter over the Askar’s objective and aiming the scope at Sun, we quickly saw beautiful detail in the sunspots that marked the surface on July 31. Imaging was routine and easy, though seeing was poor. The telescope’s 1,057mm focal length did not allow a full disk image of our star on the ASI astronomical camera’s sensor but installing a Barlow lens we achieved some dramatic detail views. We can hardly wait to try again under better skies!

Long focal length produces a Solar image too large to entirely fit on the astronomy camera’s sensor. With quality like this, however, we won’t complain. This is Sun on July 31, 2026, imaged via white light solar filter and monochrome camera, false color applied during processing.

Nearly too large! When observing low elevation targets, the telescope fits snugly within the observatory walls. Fortunately, the tall pier and large mount elevate the assembly enough that normal observing is at a comfortable height and (M57 was at the zenith during First Light!) high elevation targets do not cause us to lay on the floor or scrape the camera there! We suspect this scope on a tripod might present some problems for high elevation object observing.

Thus far the only negative, something unanticipated, is that because of the Petzval design, an optical element is located deep within the OTA making use of our beloved Herschel Wedge a risk to the telescope; that optical element is at a point in the light path where focused and unfiltered sunlight could overheat and damage the lens! We’re working around it and will assign the Herschel to the Askar 103 when desired. As we anticipated, we’d love to have much more focal length but without collimation to worry about and high quality images to work with, we’ll hope to get by … maybe with the help of a really good Barlow lens?

Southern Moon and telescope trial

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The heavily-cratered south-eastern area of Earth’s Moon is seen here, imaged just before midnight, June 23, 2026. Stella-Luna Observatory / James Guilford

This is the southern end of Earth’s waxing gibbous phase Moon, as imaged late Tuesday night. The heavily-cratered area along the terminator includes Crater Tycho — with a central peak lit by the rising Sun — and the dark circular expanse of Clavius, with the top of its western crater wall extending into the deep shadows of the terminator. We used the old Celestron C11 for this session as we continue to evaluate its performance and condition. We continue to be concerned about whether the telescope’s focus issue is simple collimation or some more serious combination of problems.

Not in the southern area of our Moon but certainly visible, even without a telescope, is Mare Crisium, shown at the center of this image made light night June 24, 2026. Stella-Luna Observatory / James Guilford.

Afternoon sunshine enjoyed side-by-side

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The morning was filled and, though it is best to observe Sun before the heat of the day sets in, the skies were still clear this afternoon so we opened the dome. Happily, there were points of interest, particularly the two plumes of prominences on the northwest rim!

Just emerging over the eastern limb (left edge, above) is a large sunspot which should prove interesting to observe, the next time we enjoy clear skies here!

This was also our first use of a new bracket that allows side-by-side mounting and simultaneous use of two telescopes on the pier. The apparatus, made by ADM Accessories, and purchased from High Point Scientific, is sturdily-built and not excessive in weight. Presently we have the Askar 103APO and the Sky-Watcher 76Ha scopes up but will likely experiment with other configurations.

Two telescopes are installed side-by-side on the observatory mount and pier employing an ADM Accessories mounting system purchase from High Point Scientific. The arrangement allows use of two telescopes simultaneously or separately without the need for rebalancing or alignment when switching between them.

Lunar Blueprints

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The northwest quadrant of Earth’s Moon, viewed during morning daylight reveals many wonderful details with an appearance that differs from nighttime views in more than just color. A few points of interest: The crater with impressive ejecta rays at lower left is Kepler; to its right is large, distinctive Crater Copernicus with its central peaks. Just above Copernicus are the peaks of Montes Carpatus. The bright spot at upper left is Crater Aristarchus with Herodotus, just to its left. Finally, at the upper right corner, is the distinctive C-shape of Sinus Iridium.

This morning, before stowing equipment for the duration of upcoming days of cloudy weather, we aimed the 11-inch scope at Earth’s waning gibbous Moon. Images were captured at about 7:50 AM EDT, after the sky had turned to blue, lending its color to Moon as viewed from Earth.

Celestron 11-inch telescope is shown aimed at Moon — a tiny white dot — in the clear, blue morning sky.

The big Celestron SCT remains in need of adjustment or, possibly, overhaul but does deliver some pleasing results! We’ve been struggling but have not yet achieved best acceptable collimation, so the scope hasn’t spent much time on the permanent pier in the observatory.

The sort of flaw that one will see from telescopes that are out of collimation — alignment of the light path within the telescope — is stars that look a bit like comets, and focus difficulties. After several efforts we are not where we need to be with the C11 to use it as our primary observatory instrument.

Unfortunately, due to lack of space, we can have only one telescope at a time on a permanent mount beneath the dome. We are considering next steps which include acquisition of a new primary telescope, upgrading of the mount, and means of mounting two instruments at a time on the pier.

As mentioned, cloudy, rainy weather is expected to be the rule for the week ahead so the telescope is parked, and accessories stowed. We’ll be working a bit on our meteor camera and thinking about where to go from here.

Our favorite image from the morning’s “Daytime Moon” efforts shows Moon’s heavily-bombarded southwest quadrant: craters, within craters, within craters. As with the other blue sky image shown here, this one is darker and more vivid than its actual appearance; we couldn’t resist giving the picture a bit more “snap” to bring out detail.
This image of the northwest quadrant of Earth’s Moon shows the image as a photographic negative — amber in color, not blue as in a previous post. Ejecta rays are especially visible around Crater Kepler, near the center of this picture. We enjoy images like this because they feel like a throwback to the early days of astrophotography, and because they tend to reveal delicate details — I mean, just look at the ejecta rays around the craters, especially Kepler just below center of this picture.

A fine day for some solar astronomy and a fond farewell to AR4079

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Our temporary observing setups are assembled on the base/floor of the planned observatory. The light orange bucket, at center, protects an empty electrical conduit that will provide utility power to a permanent pier that will be installed there. In the foreground is a table supporting a light shield for the laptop computer. The large tripod next to the table supports the white light imaging scope. In the background is the Sky-Watcher SolarQuest mount with our Coronado hydrogen-alpha solar scope attached.

We’re still doing open-air astronomy though we have a nice, solid, clean, and level space to set up our gear! This is the setup we were using today to record the sunspot at active region 4079 as it is about to roll over the solar limb/horizon. Fortunately, though it’s a very temporary setup, the portable gear we use for casual solar imaging is fairly easy to set up.

From an unusual vantage point, a picture of the solar setup used today to record the passage of active region 4079 toward Sun’s horizon. The red object is the planetary camera.

We continued experiments to determine what gear will work together for imaging. There were a few surprises and there’s need for more experimentation. What we settled on for today’s solar efforts is pictured above and includes: Askar 103 APO telescope, Meade LXD75 Goto Mount, TeleVue 2X Barlow, Baader Planetarium Safety Herschel Wedge, and ZWO ASI678MM monochrome planetary camera.

The sun as it appeared at 11:32 AM EDT on May 10, 2025. Sunspot/Active Region numbers are labeled in this image with AR4079 very near the solar western limb or edge.

Although the sky was clear, seeing was a bit shaky so once again, sharpness wasn’t what we’d like. Still, in all, we got the shot we wanted and learned a few things about our astronomy equipment. Also, the sky was blue, the air was pleasant, and birds were singing, so not a bad way to spend a couple of hours.

A closeup view of the sunspot at AR4079. There is a bright line splitting the dark central umbra of the sunspot, the gray penumbra radiating in filaments around it. White cloud-like areas surround the sunspot, especially to its north; called plage, they are associated with areas of concentrated magnetic field.