The ClearNightSky forecast didn’t look very good, but I decided to try and view comet C220P/McNaught again. I programed the comet’s new RA/Dec coordinates (02h48m40s, +09°32’56”) as a manual target. Then set up overnight plans in Singularity for the Vespera telescopes to observe the comet. The first attempt started at 03:30 then repeated every 20-30 minutes.
According to the Comet Observers Database (COBS) the visual magnitude of the comet was 8.4 for the night. My images from the previous night (20260810) were better because the seeing conditions were much better. The forecast for the next few nights doesn’t look good for more observations.
The following slideshows include the straight out of the telescope (SOOT) images and images processed with PixInsight or Sky Color Studio (included with the Vaonis Singularity application). For scale, I’ve included annotated and cropped images (0.5° FOV width). All of the images including the 16-bit RAW/TIFF files are available on my PhotoShelter site (20260811). Click on the i below the slideshow to view the image captions.
Before an observation session starts, the Vespera telescope initializes. It aligns itself to the sky and focuses the stars on the digital sensor. Once the observation session starts, the telescope continues to recheck that it is pointing at the target, and the stars remain in focus. The telescope records every good observation and adds them to the image stack. Faulty images containing clouds, stray light, and jet trails are automatically filtered by the telescope and not added to the image stack. The telescope stops an observation session after several minutes of repeated problematic images. If time remains in the overnight sequence, the telescope will attempt to restart the observation.
The Vespera telescopes did initialize and managed to get a few observations of Comet 220P/McNaught during a few breaks in the clouds. If the telescopes were not automated, I probably would have given it up for the night. The successful observations were only 8-10 minutes of frames collected, so the comet is not very bright and there still is significant background noise in the images. The Vespera 3 got the best image for the night. The straight out of the telescope (SOOT) JPG images from the Vespera Pro and Vespera Pro 2 have bright gradient backgrounds in the center of the image. Processing the 16-bit RAW/TIFF images with PixInsight (Gradient Correction) removes the bright center background. The workflow I use with PixInsight also includes Spectrophotometric Photometric Calibration (corrects white balance), and NoiseXterminator (noise reduction).
For comparison, I also processed the Vespera 3 observation of comet 220P/McNaught with the Sky Color Studio (SCS) application included in the current version of Singularity. Sky Color Studio processes the 16-bit RAW image within the Singularity application. I am running the program on a Samsung Android tablet (it does not run on Windows). The SCS application provides an 8-bit JPG image output that can be saved locally or uploaded. I saved one version of the image with no adjustments. The comet is brighter than the JPG SOOT image with the bright center background gradient more noticeable. I also processed the image with denoise (100%) and adjusted the contrast (+20%). That reduces the background gradient but also dims the comet.
Links to my previous observations of comet 220P/McNaught: 20260606, 20260609, 20260616, 20260810
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