The ClearNightSky forecast looked good for the night. I’ve not had many good observation nights in a row all spring and summer. I set up the Vespera telescopes to observe several targets including comet 220P/McNaught. Since the comet is moving relative to the other stars, every night I need to update comet coordinates (RA/Dec 02h 57m 06s, +09° 31′ 49″) in Singularity as manual targets for each telescope. The manual target settings also included type: nebula; exposure time: 10 sec; and gain: 20 db. I then set up the overnight observation plans in Singularity for each Vespera telescope. After observing the other targets, the first comet observation started at ~02:30. I’ve posted time-lapse videos of the overnight sky (180° and 360°) 20260816.

All of the telescopes were able to make several observations of the comet. Other than the position in the sky, the comet hadn’t changed much since the previous night (15-August-2026). It still has a bright green head, dust cloud, and tail. According to the Comet Observers Database (COBS) the visual magnitude of the comet was 9.1 for the night.

The following slideshows include the straight out of the telescope (SOOT) images and images processed with PixInsight or Sky Color Studio. 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 (20260816). Click on the i below the slideshow to view the image captions.

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Vespera Classic Telescope

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Vespera II Telescope

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Vespera III Telescope

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Vespera Pro 1A Telescope

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Vespera Pro 1B Telescope

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Vespera Pro 2 Telescope

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The unprocessed (SOOT) jpg images have a significant center of the image background gradient that obscures the tail of the comet. I set the BalENS (Enhanced Imaging Technology) mode for Vespera Pro (1A) to “classic”, Vespera Pro (1B) to “Recommended” and Vespera Pro 2 to “Recommended”. I don’t see much difference in the background center gradient in the unprocessed (SOOT) jpg images. BalENS is only supposed to impact the screen and the saved JPG images created by the telescopes. Processing the images with Sky Color Studio reduced but did not eliminate the center gradient.

I was able to eliminate the center background gradient issue with PixInsight using the Automatic Background Extraction process. The Gradient Correction process also works. My workflow with PixInsight also includes the Spectrophotometric Photo Callibration for white balance and NoiseXterminator for noise reduction.

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Links to my previous observations of comet 220P/McNaught: 20260606, 20260609, 20260616, 20260810, 20260811, 20260815