Chasing Comet Lemmon

Last October, excitement was building in the astronomy community about Comet Lemmon (C/2025 A3), which was predicted to reach around 3rd magnitude – bright enough to be seen with the naked eye from a dark site. As the comet’s closest approach to Earth drew near, I began planning a photography mission to capture this icy visitor. With the closest approach set for October 21, I kept a close eye on the weather for Monday the 20th. The forecast was uncertain, with a storm system expected to clear just in time for the evening. I decided to focus on photography, using my trusty 7x50 Celestron binoculars for visual observation. After dusting off the Star Adventurer Tracker – dormant since my trip to the 2023 Annular Eclipse in New Mexico – I began scouting locations within a few hours’ drive.

A light pollution map led me to the Zumbrun Overlook in Green Ridge State Forest, between Hagerstown and Cumberland. Online photos showed a promising platform with a clear western horizon. I opted for an overnight trip, staying in Cumberland to avoid a late-night drive home. I reached out to my astro-photography friend Steve, but he was busy with another shoot. Fortunately, Deb was interested in joining, and we looked forward to enjoying the fall foliage on our drive. After morning appointments, we headed west on I-70, stopping for lunch in Hagerstown before arriving at our hotel in Cumberland.

Zumbrun Overlook

After checking in, I drove out to the Zumbrun Overlook near Flintstone to get familiar with the site. The spot looked ideal, though a tree at the front of the platform meant I’d need to choose my position carefully depending on the comet’s location. My goal was to set up by 6:15 p.m., but dinner at Puccini’s ran late, and I arrived at the overlook around 6:30 p.m. At the overlook, two amateur astronomers from NOVAC had already claimed the front row, so I set up behind them. The sky was very clear, with moderate winds and a limiting magnitude of about 5.5. As twilight deepened, Comet Lemmon became visible in Boötes, just above and to the right of Arcturus. The clouds cleared just in time, and although I had to shoot over the NOVAC observers, the Star Adventurer tracker performed well. Deb joined me at the overlook to enjoy the overhead Milky Way, which was on full display.

Around 7:45 p.m. I spent some time observing Comet Lemmon through 7x50 binoculars. The comet showed a bright coma with a tail extending roughly 1.5° northeast. No greenish color was detected; the coma appeared white. I estimated its brightness at about 4th magnitude – just visible with averted vision. The scene was enhanced by the presence of orange r Boo and blue s Boo in the field. One of the NOVAC astronomers also graciously shared a view of the comet through her 8” SCT (but it seemed to lack a sharp focus).

Comet Lemmon Amid Boötes

Arriving back home the next day I was disappointed to discover my images were slightly out of focus. I salvaged them somewhat using BlurXTerminator in PixInsight on each individual shot before stacking them in Sequator. Despite some streaky clouds photobombing Lemmon, the final image captured was reasonable and serves as a wonderful memento from that night. While not spectacular, Comet Lemmon 2025/A3 was a wonderful visitor from the deep freeze of our outer solar system.