Comets are chunks made of ice, frozen gases and dust (like dirty snowballs). The come from the outer regions of our solar system. When the get close to the Sun they heat up and evaporate. This evaporating gas and dust is blown away by the solar wind and forms the tails of a comet. Therefore the tail always points away from the Sun. Comets are very common but only a few of them get that close to the Earth that they can be seen with naked eye. See also time lapse movies of comet Neowise C/2020 F3.
Fig. 1: The Surprise Comet C/1996 B2 Hyakutake was physically not as large as Hale-Bopp but came much closer to Earth, passing over the celestial north pole. Through a telescope, you could actually watch it moving past the stars. It was discovered on January 30, 1996, by Japanese amateur astronomer Yūji Hyakutake and surprised everyone who was eagerly anticipating the arrival of C/1995 O1 Hale-Bopp. — Minolta SRT-101, Kodak Ektachrome 400, 28 mm, f/4, March 24, 1996. — EXIF: LS-50
Fig. 2: The Surprise Comet C/1996 B2 Hyakutake was physically not as large as Hale-Bopp but came much closer to Earth, passing over the celestial north pole. Through a telescope, you could actually watch it moving past the stars. It was discovered on January 30, 1996, by Japanese amateur astronomer Yūji Hyakutake and surprised everyone who was eagerly anticipating the arrival of C/1995 O1 Hale-Bopp. Photo manually guided using a telescope and crosshair eyepiece on the comet's core. — Minolta SRT-101, Kodak Ektachrome 400, 300 mm, f/4.5, March 24, 1996. — EXIF: LS-50
Fig. 3: The wonderful comet Hale-Bopp with a blue gas tail and a grey dust tail. Guided with a telescope. Minolta SRT-101, Minolta MC 300mm f/4.5, Kodak Gold 400, Raten, April 1st, 1997 — EXIF: LS-50
Fig. 4: The wonderful comet Hale-Bopp with a blue gas tail and a grey dust tail. Unfortunately some branches of a tree are in the picture. Back then without digital cameras I noticed that only after development of the film. Combination of three pictures. Guided with a telescope. — Minolta SRT-101, Minolta MC 300mm f/4.5, Kodak Gold 400, Raten, 1 April 1997
Fig. 5: Comet Hale-Bopp above the woods on the Raten. — Minolta SRT-101, 50mm lens, 1 April 1997
Fig. 6: The core of the comet Hale-Bopp. Combination of five pictures. — Minolta SRT-101, Vixen Refraktor d=90mm f=1000mm, 1+2+4+8+16s, Fujicolor Super G 400, Raten, 2. April 1997
Fig. 7: The core of the comet Hale-Bopp. One can see a kind of "shock wave" caused by evaporating gas on a rotating core. Combination of three pictures with eyepiece projection. — Minolta SRT-101, Vixen Refraktor d=90mm f=1000mm, 16+30+60s, Fujicolor Super G 400, Raten, 2. April 1997
Fig. 8: The comet is rising behind the transmission tower on top of Geissberg (Goat Mountain). Composite of 33 single exposures with 22 dark frames with Starry Landscape Stacker 1.8.0. See also my timelapse movie on YouTube. — EXIF: Nikon D3; Δt=6 s; f=70 mm; f/4.0; ISO 3200; 2020-07-10 2:57:35
Fig. 9: Shooting the comet C/2020 F3 Neowise at dawn on Bözberg im canton Aargau. In the background the transmission tower on top of Geissberg (Goat Mountain). See also my timelapse movie on YouTube. — EXIF: Nikon D3; Δt=6 s; f=24 mm; f/4.0; ISO 1600; 2020-07-10 3:53:06
Fig. 10: The comet C/2020 F3 Neowise at dawn on Bözberg im canton Aargau. In the background the transmission tower on top of Geissberg (Goat Mountain). See also my timelapse movie on YouTube. — EXIF: Nikon D3; Δt=6 s; f=70 mm; f/4.0; ISO 1600; 2020-07-10 4:03:13
Fig. 11: HDR composite of the comet C/2020 F3 Neowise. 10 x ISO 800 20s + 10 x ISO 800 10s + 10 x ISO 800 5s + and 3 dark frames each. Post processing with Starry Sky Stacker, Photomatix Pro, Photoshop. Shot on 10 July 2020 on Bözberg in canton Aargau. Nikon D850 with Nikkor 300mm 2.8D, guided on a Vixen GP-DX mount with FS2 controller.
Fig. 12: Rise of comet C/2020 F3 Neowise behind the transmission tower on top of Geissberg (Goat Mountain). Composite picture of multiple single frames. See also my timelapse movie on YouTube. — EXIF: 2020-07-10 2:48:41
Fig. 13: Composite picture made of ten single frames of the comet C/2020 F3 Neowise. See also my timelapse movie on YouTube. — EXIF: Nikon D850; Δt=20 s; f=300 mm; f/2.8; ISO 800; 2020-07-10 3:17:47
Fig. 14: Composite image of comet C/2020 F3 Neowise. 10 exposures at ISO 1600 for 4 seconds with Nikon D850 and Nikkor 300mm 2.8D at f/4. 4 dark frames. 1 flat frame. Guided with Vixen GP-DX mount. Unfortunately the faint ion tail is not visible. It was taken at dusk and later that night there were thin clouds coming. 13 July 2020, Bözberg. — EXIF: Nikon D850; Δt=4 s; f=300 mm; f/4.0; ISO 1600; 2020-07-12 23:13:06
Fig. 15: Composite image of comet C/2020 F3 Neowise. Comet: 10 frames at ISO 3200 with 10 seconds exposure time. Nikon D850 with Nikkor 300mm 2.8D at f/2.8, guided with Vixen GP-DX mount. Forest in the foreground without guiding used as mask. 13 July 2020, Bözberg.
Fig. 16: Despite some cirrus clouds passing over the sky I could create this composite of comet Neowise. It shows the travel distance of the comet during a time of 20 minutes. Reprocessed 2024 using PixInsight: Stack and alignment of 50 pictures (plus dark, flat, bias) and tracking on comet core. Postprocessing with Photoshop. ISO 800, 20 seconds exposure time, interval 25 seconds. Nikon D850 with Nikkor 300mm 2.8D at f/2.8. 19 July 2020, Bözberg.
Fig. 17: I'm not quite sure if the dark stripe left of the ion tail an artefact caused by image processing or actual the comets shadow in its own clowd of dust. The star trails show the comets movement during a time period of 40 minutes. Stack of 67 frames with ISO 800 and 30 seconds exposure time, stacked aligned on comet core with Nebulosity from Stark Labs. Postprocessing with Photoshop. Nikon D850 with Nikkor 300mm 2.8D, Ibergeregg, Switzerland 20 July 2020
Fig. 18: Comet C/2020 F3 Neowise - post-processing 20 July 2023 as an exercise with PixInsight and Photoshop. PixInsight: Calibrate bias, dark, flat frames, align approx. 100 images to comet nucleus, integrate, adjust histogram, extract dynamic background. Photoshop: Fine tune highlights, shadows, colours, noise. Nikon D850 with Nikkor 300mm 2.8D at f/2.8, Ibergeregg, Switzerland 20 July 2020.
Fig. 19: 16 frames with ISO 800 and 30 seconds exposure time, stacked aligned on stars with Nebulosity. Nikon D850 with Nikkor 300mm 2.8D, Ibergeregg, Switzerland, 20 July 2020
Fig. 20: Shot on 13 October 2024 near Cheisacher Observatory in Aargau. Unfortunately the comet drowned in the cirrus clouds afterwards. I could have used 1s exposure time without star trails. — EXIF: Nikon D850; Δt=1/2 s; f=300 mm; f/2.8; ISO 3200; 2024-10-13 19:44:36
Fig. 21: Shot on 13 October 2024 near Cheisacher Observatory in Aargau. Unfortunately the comet drowned in the cirrus clouds afterwards. Unguided capture on a tripod. I could have used 1s exposure time without star trails. — EXIF: Nikon D850; Δt=1/2 s; f=300 mm; f/2.8; ISO 3200; 2024-10-13 19:47:20
Fig. 22: Shot on 14 October 2024 near Cheisacher Observatory in Aargau. Comet C/2023 A3 Tsuchinshan-ATLAS was mostly behind clouds. One can see trails of those bloody Elon Musk Starlink satellites. Single exposure guided on a Vixen GP-D2 equatorial mount. — EXIF: Nikon D850; Δt=20 s; f=300 mm; f/2.8; ISO 200; 2024-10-14 20:07:49
Fig. 23: Shot on 14 October 2024 near Cheisacher Observatory in Aargau. Comet C/2023 A3 Tsuchinshan-ATLAS was mostly behind clouds. One can see trails of those bloody Elon Musk Starlink satellites. Single exposure guided on a Vixen GP-D2 equatorial mount. — EXIF: Nikon D850; Δt=20 s; f=300 mm; f/2.8; ISO 200; 2024-10-14 20:10:19
Fig. 24: Shot on 14 October 2024 near Cheisacher Observatory in Aargau. Comet C/2023 A3 Tsuchinshan-ATLAS was mostly behind clouds. One can see trails of those bloody Elon Musk Starlink satellites. Single exposure guided on a Vixen GP-D2 equatorial mount. — EXIF: Nikon D850; Δt=20 s; f=300 mm; f/2.8; ISO 400; 2024-10-14 20:13:42
Fig. 25: Single frame of a timelapse showing setting comet C/2023 A3 Tsuchinshan-ATLAS. The full moon illuminated the landscape and the comet was barely visibly by naked eye. — EXIF: Nikon D850; Δt=6 s; f=35 mm; f/2.8; ISO 400; 2024-10-17 19:46:34
Fig. 26: Single frame of a timelapse showing setting comet C/2023 A3 Tsuchinshan-ATLAS. The full moon illuminated the landscape and the comet was barely visibly by naked eye. — EXIF: Nikon D850; Δt=6 s; f=35 mm; f/2.8; ISO 500; 2024-10-17 20:35:04
Fig. 27: Creating a timelapse showing setting comet C/2023 A3 Tsuchinshan-ATLAS — EXIF: iPhone 15; Δt=1 s; f=5.96 mm; f/1.6; ISO 1600; 2024-10-17 19:47:08
Fig. 28: Comet C/2023 A3 Tsuchinshan-ATLAS — EXIF: iPhone 15; Δt=1/2 s; f=5.96 mm; f/1.6; ISO 3200; 2024-10-17 20:24:06
Fig. 29: Stack of only three pictures in a row without Starlink satellite trails or clouds. Each of 20s exposure time. See timelapse — EXIF: Nikon D850; Δt=20 s; f=300 mm; f/2.8; ISO 1600; 2024-10-20 19:47:11
Fig. 30: My equatorial mount Vixen GP-D2 with heavy tripod and mounted Nikon D850 with Nikkor 300mm f/2.8 telephoto lens pointing to comet C/2023 A3 Tsuchinshan-ATLAS. — EXIF: iPhone 15; Δt=1 s; f=5.96 mm; f/1.6; ISO 8000; 2024-10-20 19:50:32
Fig. 31: Stack of 28 single frames using Pixinsight: Weighted Batch Preprocessing, Comet Alignment, Dynamic Background Extraction. Photoshop: Crop, Camera Raw Filter (Exposure, Blacks, Whites, Dynamic, Saturation, Structure, Clarity, Noise Reduction). Shot on 21 October 2024.
