By Friday October 17, 2025, Comet C/2025 A6 Lemmon had become an evening object, so my husband and I drove to Sargent, Texas for darker skies (Bortle 4).  Unfortunately, the clouds stayed near the horizon and hid Comet Lemmon.  It was quite windy out, so I didn’t want to get out my telescope.  

However, there was another bright comet in the sky, C/2025 R2 SWAN, and I also had my camera to try to capture a wide field image, so I set the camera up to capture a wide field with Comet C/2025 R2 Swan.  I didn’t have much time to capture it before it was obscured by clouds and only got 7 minutes of data.  

The comet was above the constellation Sagittarius which is in the direction of the center of the Milky Way, so it is a particularly bright section of the Milky Way and contains multiple Messier Objects, marked in magenta.  Messier Objects are Deep Space Objects that comet hunter Charles Messier put on a list of “not-comets.”  There are 17 Messier Objects in this image, four of which I have imaged before in more detail.  It’s fun to compare them to an actual comet here.  While the comet stands out with its greenness in the image, visually it would be a fuzzy spot like the others … except that it very slowly moves across the field of view.

Apparently I forgot to take flat frames for this image, so I used a synthetic flat.

Camera geek info – camera:

• Canon EOS 60D in manual mode set at f/2.8, 10 second exposure, ISO 4000
• Sigma 24-70 mm f/2.8EX lens, set at 24 mm, manual focus
• Tripod
• Intervalometer 

Frames – camera:

• October 17, 2025
  • 42 10 second lights
  • Matching darks from library