It was another clear night and two tripods and two telescopes were moved to the back section to view the comet. Each night Comet C/2023 A3 (Tsuchinshan–ATLAS) is a little bit higher in the sky but becomes a bit dimmer. The estimated magnitude of the comet was +4.9. The length of the comet tail also decreases every night. The digital sensor field of view for the first image (Vespera Passengers ) with the comet head near the center is 2.4° x 1.8°. For the second image (Vespera II) I was able to get the comet head closer to the bottom. The diagonal field of view for this sensor is 2.5° x 1.4°.
Comet C/2023 A3 (Tsuchinshan–ATLAS). Composite of 30 images taken with a Vaonis Vespera-Passengers Telescope (200 mm, f/4, 30 x 10 sec).Comet C/2023 A3 (Tsuchinshan–ATLAS). Composite of 30 images taken with a Vaonis Vespera II Telescope (250 mm, f/5, 30 x 10 sec) using a CLS (city light suppression) filter.
I returned to the far corner of my backyard with a view to the west where Comet C/2023 A3 (Tsuchinshan–ATLAS) was still high enough above the trees be visible just after dusk. The estimated magnitude of the comet was +4.7. I couldn’t see it directly, but easily captured an image with Vespera Pro telescope. This is a composite of 30 stacked 10 second images (300 second exposure).
Comet C/2023 A3 (Tsuchinshan–ATLAS). Composite of 30 images taken with a Vaonis Vespera-Pro Telescope (250 mm, f/5, 30 x 10 sec).
I found a spot in the far corner of my backyard with a view to the west where Comet C/2023 A3 (Tsuchinshan–ATLAS) was still high enough above the trees after dusk to be visible. The estimated magnitude of the comet was +4.5. To me barely visible to the eye, but easily captured by camera or Vespera telescope.
To observe a comet with the Vespera telescopes, you first need to determine the RA (right ascension) and Dec (declination) coordinates of the comet for your location at the time of the observation. I use Stellarium find this information. The RA/dec data is needed to create a manual observation target in the Singularity application that controls the Vespera telescopes.
The Vespera telescopes weigh about 5 kg (11 lbs) and could easily be carried to the far corner of my backyard and set up on heavy duty camera tripods. The only thing I needed to worry about was a doe that found a hole in my deer fence and was wandering around in the back yard. Once it was dark enough to initialize (automatically align and focus) the Vespera telescopes all I needed to do set it to look for the manual target and start acquiring and stacking images.
The comet was much brighter than the other stars in the field of view. The comet’s tail was longer than the field of view of the telescopes. Vespera Classic (1.6° x 0.9°) and Vespera Pro (1.6° x 1.6°). The jpg images were processed to increase the brightness (Capture One Pro) and reduce the noise (Topaz AI).
Comet C/2023 A3 (Tsuchinshan–ATLAS). Image taken with a Hasselblad 907x camera and 25 mm f/2.5 lens (ISO 800, f/8, 32 sec). Processed jpg image with Capture One and Topaz AI (denoise). Cropped to 8k x 8k (~60° field of view).Comet C/2023 A3 (Tsuchinshan–ATLAS). Image taken with a Hasselblad 907x camera and 25 mm f/2.5 lens (ISO 800, f/8, 32 sec). Processed jpg image with Capture One and Topaz AI (denoise). Cropped to 2400 x 2400 pixels (~ 18° field of view).Comet C/2023 A3 (Tsuchinshan–ATLAS). Composite of 30 images taken with a Vaonis Vespera Classic Telescope (200 mm, f/4, 30 x 10 sec).Comet C/2023 A3 (Tsuchinshan–ATLAS). Composite of 30 images taken with a Vaonis Vespera-Pro Telescope (250 mm, f/5, 30 x 10 sec).
