Single exposure image of Comet C/2025 A6 (Lemmon), October 20, 2025. Tech: Canon EOS 5D Mk. 4 DSLR, 400mm lens, f/5.6, ISO 10,000, 4 seconds.
October 21, 2025 — It was a tough one to find but, after a good deal of effort under near-pristine (for us) skies, I was able to spot the comet C/2025 A6 (Lemmon) from a Medina County, Ohio park. This (above) is a quick edit of a single frame. Star tracking wasn’t what it should have been; I’ve got to get more practice in the field! I worked on combining multiple frames the next morning, attempting to create a better quality image.
Stacking RAW images of C/2025 A6 (Lemmon) I did what I could to pull the most out of the imagery. What we got was a somewhat “cleaner” version. Not spectacular but the best we could do given all circumstances. I hope to learn improved processing skills and revisit the source images in the future. In the meantime, though the pictures are not spectacular, I’m happy to have bagged another comet. After all, how many of them do most of us see in a lifetime? These were recorded the night of October 20 but the UTC time conversion moves the date to the 21st.
Stacked image of Comet C/2025 A5 (Lemmon), October 20, 2025A SkySafari chart showing the position of Comet C/2025 A6 at about 7:30 PM EDT, October 20, 2025, as viewed from Northeastern Ohio.
November 3, 2025 — The air was still and the moon so bright and clear tonight, we had to open up the observatory long enough to take a peek and a pic! Moon was 92% illuminated in its waxing gibbous phase, lighting the landscape around us, no flashlight required. Technical: Askar 103 APO telescope, TeleVue Powermate 2X Barlow, Canon EOS 5D Mk. 4 DSLR, single exposure.
A full-disk image of Sun, as recorded in hydrogen-alpha light. Visible are two large sunspots, several serpentine filaments, and prominences that appear around the star’s limb. Credit: Stella-Luna Observatory / James Guilford
October 3, 2025 — We had been having quit a lot of trouble lately, recording data and reproducing images of Sun with prominences. There was some early success but even those images were a struggle to produce. Taking a look at suggested camera settings found in an article on solar imaging, one thing stood out — gain! We had nudged the camera’s gain setting upward and that’s not helpful and certainly not recommended; the setting should be very low or even zero! A few adjustments in data capture parameters was all it took to make a big difference in image processing and results!
Sun’s northwest quadrant, as recorded in hydrogen-alpha light. Visible are several filaments, as three prominences appear along the star’s limb. The “peach fuzz” appearance of the edge of the solar disk is caused by the presence of innumerable spicules or small prominences.
We’re very pleased with Barlow-boosted views, shown here, though we’re still having some issues with achieving even lighting across whole-disk views — just can’t seem to get them tuned right with the Coronado SolarMax III. Visual observing was also very good, especially with the TeleVue 10mm eyepiece. October 3 conditions: Clear sky, temperature of 74°F, light southeast wind.
A close-up view of two large sunspots, as seen in hydrogen-alpha light. Solar plasma follows the intense and curved lines of magnetic force to highlight the turmoil in the vicinity of the spots.
An International Observe the Moon Night promotional graphic. Credit: NASA
Note: The observatory construction is essentially complete with only a few “touch up” items and further outfitting remaining. We’ll eventually get around to writing and illustrating the story of the project. First, though, the 2025 International Observe the Moon Night….
October 4 marked International Observe the Moon Night (IOMN), an event billed as an opportunity to “unite people across the globe in a celebration of lunar observation, science, and exploration.” Coordinated and promoted by NASA, IOMN boasted 1,045 registered events worldwide. That count does not include informal events and individuals who, on their own, observed Earth’s Moon, encouraged by the promotion. Unfortunately, due to a U.S. government shutdown, NASA staff are unable to update the IOMN website and we may never know how it went this year.
While we did not host an outreach event, we did post fresh, new telescopic images depicting lunar details, along with descriptions of those events as our participation. This year, we concentrated our efforts on the Threads social media platform. What follows is what we posted.
Here’s a nice full-disk view of Earth’s Moon, one we made a few months ago with a phase very close to what we see tonight. The phase is called the “waxing gibbous” and is seen between the First Quarter and Full Moon. Moon will reach its full phase the night of October 6, this year.Mare Humorum, aka Sea of Moisture, is the dark circle at the center of this image. It was formed in an impact by an asteroid or comet, the crater filled with basalt. The “sea” is about 264 miles across and is seen here near the terminator — the dividing line between night and day — not long after local lunar sunrise. Crater Gassendi is the circular ring that intersects with Humorum. The crater is about 69 miles in diameter; a smaller crater at its northern edge is called Gassed A.
Followup Edit: Spellcheck was convinced we meant to type “Gassed” when what we really wanted was Gassendi A. Maybe it was the chili we had for dinner. Here’s crater Tycho, prominent even in the heavily-bombarded southern lunar highlands. Estimated to be 108 million years old, Tycho is about 53 miles in diameter but easily spotted using binoculars or a small telescope. The crater’s vast field of ejecta rays — the spray of material “splashed” out when an object hit Moon — is bright and forms lines that lead back to their origin. The feature was named after Danish astronomer Tycho Brahe.Also near the terminator, in Moon’s northwest, is this beautiful pair of craters: Kepler (left) and Copernicus. Like Tycho, Copernicus is marked by the prominent lines of ejecta radiating from the impact site, a crater about 58 miles in diameter. Crater Kepler, about 20 miles wide, lies to the west of Copernicus with its western rim shining brightly in the light of the lunar sunrise. For our final image of the night, we’re posting our image of a complex area of Moon at the northern end of the terminator. In the upper right we see crater Anaxagoras and surroundings glowing brightly, contrasted against the stark blackness of space. The smooth band spanning the image is Mare Frigoris. “C” shaped arch marks Sinus Iridum, opening to Mare Imbrium. Crater Plato is the circle with a smooth, dark floor in the lower right. Notice the chain of smaller, satellite craters next to Plato.
Crater Plato is about 63 miles in diameter and about 3.84 billion years old. Once again, see how the western rims of the craters along the terminator shine in the low-angle light from the rising Sun.
We hope you have enjoyed what you have seen and will see online tonight, or were fortunate to attend an International Observe the Moon Night event in person. Outdoors, at home, online, or wherever you may be, we’re glad to have had you with us. We hope IOMN has united people across the globe in a celebration of lunar observation, science, and exploration, under one sky, appreciating one Moon. Goodnight, and keep looking up!
Our neighborhood star: The Sun. Photographed in hydrogen-alpha light, this image shows the roiling chromosphere of our star with a large filament parallel with the left-hand edge of the picture, sunspots strung vertically across the center, and a good number of prominences along the rim, glowing against the dark background of space. Image has been rotated — east is up, north is right. Imaged 2024-10-26. 18:43 UTC. Credit: James Guilford, Stella-Luna Observatory
White light allows viewing Sun as if we could stare directly at it without the resulting blindness. The Herschel wedge does much the same thing but with, perhaps, a bit more contrast and detail. Both of those white light views allow us to see a layer of the solar atmosphere called the photosphere. In the photosphere the most apparent details are sunspots, standing black against a white background. With enough resolution we can also see granulation — enormous convective bubbles of searing solar plasma.
One layer above the photosphere — yes, above — is the chromosphere. Shining in the wavelength of hydrogen-alpha (Ha), the chromosphere is not visible to us without light filters that exclude all light but Ha. A wholly different view of our Sun is available in that wavelength. Swirling seas of plasma form curves and hash as they are moved by magnetic fields, long filaments float over those seas, as fountains of glowing gas arc from the solar disk contrasted against the blackness of space. On closer examination, the solar limb appears rough, a bit like a fine-toothed saw blade, as innumerable spicules, jets of glowing gas, are seen in contrast. Yes, sunspots are visible but are no longer the primary interest.
After many tries and failures at processing images to best show the chromosphere complete with prominences, I finally learned what some other imagers were using to process their images: Solar Toolbox — a package of programming scripts used with the PixInsight imaging application. I still have much to learn about Toolbox but it has already been enormously helpful to me in the challenging world of solar imaging! Thus, the image above is from very good data recorded about seven months ago, now reprocessed using Toolbox.
Monday dawned clear and bright so we set up the hydrogen-alpha (Ha) solar telescope and recorded some image sequences. Today was a dull and cloudy day so we spent some time learning new processing techniques for our solar imaging and were rewarded with our best shot yet. The processing of choice was Solar Toolbox — a script package developed for use in PixInsight software — just the set of tools we were looking for! We’ve a long way to go but we think this picture shows great progress!
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.
The Sun, as it appeared on April 17, 2025, in hydrogen-alpha light. The image was recorded using a Coronado solar telescope, a Sky-Watcher SolarQuest mount, and a ZWO ASI 678MM camera. Photo by James Guilford.
Taking advantage of midday clear skies, Thursday, we set up the hydrogen-alpha telescope and did a little observing and imaging. Seeing conditions were only good but we could make out several prominences along Sun’s limb. (The proms did not record well and we need to figure out how to enhance their visibility in our images.) Most notable, however, was the shear number of filaments in Sun’s northern hemisphere. None visible in the south! Fragments of exploding filaments launched from Sun and produced two CMEs that, when they reached Earth on April 16, caused strong geomagnetic storm activity and widespread auroras. The storm, however, died out before northern lights could be seen here.
The Sky-Watcher SolarQuest mount is shown here aiming our Coronado 60mm hydrogen-alpha solar telescope at Sun.
Aiding in our efforts was a device we used for the very first time in this session: The Sky-Watcher SolarQuest with its HelioFind system. The device is lightweight, easily supported our rather robust Coronado solar telescope, and was exceptionally easy to learn and operate. Essentially, all that was needed was to set the tripod up so that it was level, turn the device on, and let it do its thing! It is powered by four AA batteries, placed inside the unit. As an alt-az mount, no counterweights or muliti-axis balancing was needed; just mount the scope with its balance point at the center of the dovetail clamp. No remote control, no app, the compact and self-contained SolarQuest established GPS contact, leveled the scope, then looked for Sun. The SolarQuest turned and elevated the telescope, quickly acquiring our nearest star. When the motion stopped, we looked through the eyepiece to discover Sun well within the field of view. A few nudges of the system’s adjustment buttons and Sun was centered. Tracking was excellent throughout the observing/imaging session. Provision is made for further refinement of tracking but that adjustment was unnecessary for the day’s activity. The SolarQuest will make our daytime astronomy a whole lot more convenient and enjoyable!
A business-class jet airplane trailing twin contrails is seen in silhouette against the roiling surface of the sun. The image is recorded in hydrogen-alpha light. Photo by James Guilford.
We had just finished setting up for some solar astronomy and tapped the button to begin a video sequence when something flashed across the computer screen. A jet appeared for less than a second, contrails briefly persisting, silhouetted against the roiling solar disk! We’ve only seen this twice while observing Sun, this being the second time, and we only captured this image by shear luck. The first time we witnessed a solar “photo-bombing” was under similar circumstances. Previously, we had completed setup, was refining focus, and just about to begin recording exposures. We missed imaging that encounter by about the same interval as we succeeded this time!
The total lunar eclipse of March 13 – 14, 2025 did not disappoint! We resolved to capture images from the late partial eclipse to maximum eclipse, mostly to be able to fit in a little sleep! Catching it all, which we could from our North America location, would have required, essentially, an all-night session. Just a bit too much!
Early partial eclipse. The brighter shadow within the penumbra lights the top portion of this image. Note a bit of reddish tone within the dark umbra. 2:08 AM EDT
I sat on a pad over the paved surface where in the cold, where the observatory is to eventually stand. The old telescope mount ticking away as it tracked the moon across the sky. Occasionally geese and ducks on the nearby pond called out against some unseen disturbance. The stars of Great Orion were sinking behind nearby trees.
Moon is deep within the umbra and last penumbra light about to be left behind. 2:19 AM EDT
In the otherwise quiet chill, I watched the lunar transition, from a bright sliver left over from the night’s Full Moon, to glowing copper orb. With a cable release I manually triggered the camera’s shutter: click — pause — click, to record the event.
Maximum eclipse. Moon is fully within the umbra but because it is not traveling through the center of Earth’s deepest shadow, scattered light from the penumbra brightens the upper limb. 2:58 AM EDT
Shortly after maximum eclipse (shown above), at 2:58 AM EDT, I shut down the telescope and, casting a wistful eye at the still-darkened Moon, went indoors. I fed the waiting cat, changed back to pajamas, and returned to bed. In fitful sleep, somehow still cold, happy to have sacrificed rest for the experienced phenomenon.
Tech: Askar 103 ED telescope, Canon EOS 5D Mk 4 camera, Meade Goto Mount, Photoshop. ISO 400, variable exposure times.
Only a few minutes from occultation, Mars is seen just off the lower edge of the lunar limb in this full-disk image recorded at 9:09 PM EST. The event only occurs with planet Mars about once every 14 years. Photo by James Guilford.
Clouds held off — pretty much — for us to observe the Moon occult* Mars, the reddish dot in the photo above. About once every 14 years or so, everything lines up just right and planet Mars is hidden by Earth’s Moon. Though Mars is about twice as big in diameter as our Moon, it was nearly 60 million miles farther away from Earth during the encounter — to the unaided eye, Mars looked like a tiny bright red star next to the Full Moon.
As predicted by mathematics, Mars and Moon grew nearer and nearer each other until, at 9:12 PM Eastern Standard Time (EST), the Red Planet disappeared behind our brilliant orb.
Mars, the small reddish dot in this image, nearing occultation by Earth’s Moon, as seen at 9:07 PM EST, January 13, 2025. Photo by James Guilford.A red arrow indicates a ghostly mound that was Mars as it disappears behind Earth’s Moon at 9:12 PM EST, January 13, 2025. The dark oval to the right of Mars’s vanishing point is the lunar basin Grimaldi. Photo by James Guilford.
Passing clouds threatened to obscure the event but thanks to gaps between those clouds, there was enough clearing for observation. Shortly after Mars vanished, so did those inter-cloud gaps. With Moon now cloud-covered, we did not return to the 13℉ night to watch for Mars to emerge.
Technical: Canon 6D Mk. 2 Camera, Canon 400mm EF 1:5.6 L Lens, Canon 2X telextender, ISO 400, f/11, 1/250 second, photographic tripod.
*Occult: To cut off from view by interposing something. Commonly used as a noun to indicate something supernatural that is hidden from ordinary access.
Stella-Luna Observatory 