It has been a busy week shooting two very different night sky subjects. The first was to capture the Pleiades star cluster with the planet Uranus in the same field of view. I did a test shot of this a few months ago and finally dedicated an evening to capture this pairing. This was shot using a Nikon D850 and a Nikkor 180mm ƒ/2.8 Ai-S lens. This lens has become one of my favorites for short-telephoto shots of the sky. It’s pretty good wide open at ƒ/2.8 but becomes excellent at ƒ/4.0. This is a composite of 27x120second images. Image stacking was done using Siril.
Pleiades star cluster and the planet Uranus.
A few days later it was time to catch the peak of the Geminid meteor shower. The moon did not rise until well after midnight so I had plenty of time to capture meteors in the late evening. The image is a composite taken between 2100 and 2159 MST while using a star tracker — and then blended with a foreground image taken earlier. Jupiter is the bright object in the center with Pollux and Castor to its upper left. The red star on the right is Betelgeuse. The meteor at top center left a long-lasting smoke trail.
Geminids meteor show. Jupiter is in the center with Pollux and Castor to its upper left. The red star on the right edge is Betelgeuse.
Here are cropped versions of the bright meteor and the smoke trail.
A bright Geminid meteor……and the smoke trail it left.
Fortunately, it has been a warm December so far and standing around at night shooting photos is not as cold as it could/should be. It won’t last.
Solar Max continues to produce auroras that are visible at low latitudes. The most recent occurred on the night of 10–11 December. Once again, I chose to shoot from Ashurst Lake because it has very good visibility to the north. This time, though, we did not venture out to the edge of the lake. Heavy rains in November (almost 5″) has resulted in wet soils that have not dried in the colder temperatures and low sun angles of December. No desire to sink in the mud!
Shooting from the parking lot was a good alternative but did not give the expansive reflections from the lake that I have enjoyed before.
The aurora substorm starts up to the northeast with numerous pillars visible.The pillars move westward over the next few minutes. The North Star, Polaris, is highlighted here to give a sense of the low heights of these pillars.The substorm subsided leaving just a faint glow to the north. A meteor (probably a Geminid) streaks across the sky with the aurora as a backdrop.
This aurora was lower intensity and much more difficult to see than the event in November. In fact, we were unable to see it with the unaided eye. Reviewing the photo images after the event clearly showed there was a sub storm that lasted about 20 minutes. The peak heights of the pillars was much lower than we have seen before.
I have been learning how to use satellite data to forecast when these substorms might appear. Here is a plot of the data leading up to the substorm which occurred around 1918—1940 MST (0218—0240 UTC 11 December 2025). The vertical line shows when the substorm pillars first appeared in my photographs.
Solar wind data used to forecast the aurora substorm.
Images: Nikon D850, 17mm, f/2.8, ISO 3200, 15 seconds.
The Sun remains active even though it has probably passed Solar Max—and auroras once again visited low latitudes, including northern Arizona. The geomagnetic storm forecast indicated auroras were likely into the middle latitudes with a chance of appearing at low latitudes. I was ready to view the aurora but the weather was uncooperative. Clouds increased during the day and by sunset a layer of high clouds covered the region. But an hour or two later I was able to see stars overhead (but not low on the horizon) so I decided it might be worth the effort.
It was worth the effort.
As we did for the October 2024 event, we watched and photographed the aurora from Ashurst Lake near Flagstaff, Arizona. I was again hoping to capture reflections of the aurora on the still waters of the lake and was successful. I even managed to capture an image with a heron standing in the shallow water and silhouetted by the bright aurora to the north.
At first the aurora was faint and clouds in the north blocked the view. Gradually, the clouds moved out of the way. And, then, between about 2135 and 2155 MST (0435 to 0455 UTC 12 November 2025) there was a strong substorm that lit up the sky. It was bright enough to illuminate the landscape and even cast faint shadows.
The aurora was seen as far south as latitude 13°N in El Salvador!
Here are a few still images and a time-lapse video. Images were shot with a Nikon D850, Tamron 12mm fisheye lens, ISO 3200, ƒ/4, 15 seconds.
The beginning of the substorm at 2140 MST (0440 UTC). Numerous pillars are visible across the northern sky (12mm fisheye lens).A few minutes later (2148 MST; 0448 UTC) a SAR (Stable Aurora Red) arc appears above the pillars.A heron wades in the shallow water of Ashurst Lake and is silhouetted by the bright aurora in the north.
Time-lapse video from 1948–2226 MST (0248–0526 UTC). Very little activity is present at first but then the substorm erupts with numerous pillars developiing along with a SAR (Stable Aurora Red) arc the propogates upgward. And all of this is reflected in the lake.
And there may be yet more big events during this solar cycle!
Here is some additional information about this aurora and current solar cycle.
Some of the strongest and most widespread displays of auroras since Oct. 10, 2024, occurred overnight on Tuesday, Nov. 11, into Wednesday, Nov. 12, according to NOAA, caused by one of the most powerful G4-rated geomagnetic storms of the current solar cycle.
The potent geomagnetic storm occurred after two particularly fast-moving coronal mass ejections — clouds of charged particles from the sun — erupted from the sun on Sunday, Nov. 9, and Monday, Nov. 10, in the wake of an X1.7 and X1.2-class solar flares. It left space weather scientists on high alert this week.
The last three major events from the current solar cycle are shown in this table from Wikipedia:
X1.2(X1.3)-class flares[95] and X4.5-class flare.[96] The flares with a magnitude of 6–7 occurred between 30 April and 4 May 2024. On 5 May the strength of the solar storm reached 5 points, which is considered strong according to the K-index. The rapidly growing sunspot AR3663 became the most active spot of the solar cycle 25. On 5 May alone, it emitted two X-class (strongest) flares and six M-class (medium) flares. Each of these flares resulted in a short-term but profound disconnection of the Earth’s radio signal, resulting in signal loss at frequencies below 30 megahertz (MHz).[97]
With a NOAA rating of G5, an estimated peak Dst of −412 nT, and aurorae seen at far lower latitudes than usual in both hemispheres, this geomagnetic storm was the most powerful to affect Earth since November 2003. A later study estimates a Dst peak of −518 nT, meaning the strongest storm since 1989 and the second strongest since 1921.[71]
Oct 2024
October 2024 solar storm
Triggered by an X1.8 solar flare that produced a relatively fast CME.[104][105] The storm reached a peak Dst of −341 nT.[106] Auroras seen as far south as Cuba.[107]
Earlier this year I rented a Tamron SP 35mm ƒ/1.4 Di USD lens to use for shooting the Perseids meteor shower. Yes, I know, the Moon was an issue in 2025 but I wanted to test this lens. The reason I was interested in a 35mm ƒ/1.4 can be seen in this article at Clarkvision.com in which he describes the best combinations of aperture vs. focal length to maximize the number of meteors per exposure. And the choice of this particular lens was informed by this review article.
Milky Way with the Tamron 35mm f/1.4 lens. The star Vega is visible at the center bottom and the North America Nebula is located in the upper right.
While I did not capture many meteors (the Moon, remember?) I was impressed with the optical quality of this lens. In fact, I ended up purchasing the rental lens since I had already done my testing with that particular sample.
I have used this lens on a couple occasions to photograph Comet C/2025 A6 (Lemmon) in which I used tracking to get a 2-minute exposure of the comet followed by untracked to get a similar exposure of the foreground. The results were further proof that this was a very good lens with sharp stars all the way into the corners.
Earlier this month I put it to another test when I did exposures of the Milky Way and aligned the camera so that the Milky Way passed diagonally across the lens and into the corners. I then stacked ten 2-minute images using Siril.
These images were shot with the aperture wide open at ƒ/1.4, ISO 200, and 120 seconds.
Interestingly, the result was too many stars! Indeed, the wide-open ƒ/1.4 aperture captured so much light that there were too many stars so I used some star reduction techniques available in Siril. The reduction technique resulted in a very pleasing final image presented here.
This will be a useful addition to my collection of astrophotography lenses for capturing wide views (54.3° x 37.7° field) of the night sky.
There haven’t been too many opportunities to photograph the comet in the first half of November owing to a bright Moon and cloudy skies. But I did get very dark skies on the evening of November 6 and shot a sequence spanning about 15 minutes near the end of twilight and when the comet dropped below the trees. The images were stacked and aligned using Siril and then finished in Lightroom/Photoshop.
Comet C/2025 A6 (Lemmon) on 06 November 2025 with a 180 mm lens.Black-and-white negative version of Comet C/2025 A6 (Lemmon) on 06 November 2025 using a 180 mm lens.
The final image was then converted to a black-and-white negative as this format can show more of the detail in the comet’s tail. It also shows more of the satellite tracks that criss-cross the sky.
It has been fun shooting this comet and now I look forward to the next photogenic comet to grace our skies.
Nikon D850, Nikon 180 mm AI-s, f/4, ISO 200, 7×120 seconds.
