Comet C/2023 A3 (Tsuchinshan-ATLAS) has indeed become very observable with the naked eye after all. It can be photographed quite well with smartphones. Of course, a camera with a larger aperture provides a better image, not to mention the quality lenses. How to find the comet in the sky is described quite well in the Sky and Telescope article Comet Tsuchinshan-ATLAS climbs, brightens and-delights, including a map. Current information about comet can be found at http://astro.vanbuitenen.nl/comet/2023A3 .
This article is mainly to provide photos of the comet taken by RAC members and will be updated as needed. The images are listed by date and time, with the most recent at the top.
Sunday, October 27
Picture by Bob Fealey from his home observatory. Author says on forum: “Comet C/2023 A3 among the stars of Ophiuchus (R) this evening (10-27). Some stars are identified with their magnitude and SAO number or just their magnitude. Left part of the image is courtesy Stellarium.
Friday, October 25
Picture by Bob Fealey from his home observatory. Author says on forum: “The SW sky isn’t too light polluted and the comet was viewed and photographed from 8 to 9 pm. Was using my 6 inch 150P Quattro scope and ZWO183 MC camera and Sky Watcher HEQ5 Pro mount. Stacked six 5 second frames. The image below is a relative closeup of the comet when it was near star SAO 122368 in Ophiuchus”.
Wednesday, October 23
Hover your cursor over the reduced images in the row below to see the date they were taken. The images were taken with the same smartphone by Jay Mclaren and their full size is on the corresponding date below. You can see that the brightness of the comet is decreasing.
Sunday, October 20
The image of the comet below was taken with the same iPhone with the same exposure as the 10/15 and 10/17 images. But this one has a higher ISO8000 sensitivity and zoom 1.7, so it’s noticeably grainier. The author says “I looked for the comet tonight from my back yard and found it easily with binoculars. The tail is still visible although considerably fainter than it was a few days ago. It was considerably easier to see than it was last night, because of a clear sky and lack of illumination by moon.”
Friday, October 18
A shot from the backyard with a sky full of light pollution. But even in a short single two-second exposure, the comet is clearly visible. The beam of the green laser catches the eye. Even with such a short exposure, there are hints of globular clusters M10 and M12.
Thursday, October 17
Compare picture below taken on Thursday October 17 with picture by the same iPhone with the same exposure from Tuesday October 15.
As an aside, and lesion on visual perception, colors of the foreground trees and grass as well as the blue sky were quite visible in the photos with illumination from the full moon, although the scene still looked grey without the benefit of the camera. This illustrates the brightness requirements of color vision – when we use night vision (scotopic vision), the color is still there although the overall lighting is not bright enough to invoke color perception (photopic vision) and we do not see the colors. The picture with a brighter foreground was more recent, after the comet had faded and the moon was brighter. This scene was still not bright enough to see the colors in the trees, grass, and sky. The comet is in the center just above the spruce tree.
Two stars from the constellation Ophiuchus, Yed Prior and Yed Posterior (more to the left), are pictured side by side above the gap between the trees to the left of the comet’s head.
Comet C/2023 A3 on October 17 over farmland by Duane Deal. forum
Tuesday, October 15
Two stars from the constellation Ophiuchus, Yed Prior and Yed Posterior (more to the left), and Zeta Oph, Han, are shown side by side to the left of the comet’s tail. On the upper right is the constellation of the Corona Borealis (Northern Crown) with the brightest star Alphecca in the middle. Between this constellation and the comet is the constellation Serpens Caput (Head of the Serpent).
Comet C/2023 A3 on October 15 by Robert Fealey. 8 shots with iPhone, stacked, aligned, corrected the horizon, and stretched the image with curves. forum
Comet C/2023 A3 on October 15 by Robert Fealey. iPhone picture that was taken through the 50 mm finder scope-2x Barlow lens – 20 mm eyepiece concoction that was guided by my telescope mount. Some stars identified and the globular cluster M5 as well. forum
Comet C/2023 A3 on October 15 by Duane Deal. Including Messier 5. forum
Comet C/2023 A3 on October 15 by Duane Deal. This comet shot is from a mix of exposure times. I was tracking on stars, but registered the comet. I fixed the horizon but did not correct the stars (so they are trailing). Look how long that tail is. The saturation in the sky is the way the camera saw it. I actually desaturated and corrected out some of the blue.. and it’s still rather saturated and blue. The frames were a mix of exposure times (some more, some less). Mainly because my phone quit controlling my camera at the end of the night so I just clicked away in bulb mode. forum
Monday, October 14
Comet C/2023 A3 on October 14 by Robert Fealey at Root River Park. forum
Saturday, October 12
Pictures by Kirk Severson forum
Comet C/2023 A3 Tsuchinshan-ATLAS on evening October 12 by Duane Deal, 103mm 2sec f22 ISO3200. forum
Comet C/2023 A3 on evening October 12 by Josef Chlachula. forum View from 50th Ave NW I under junction with 65th St NW. At about 7:10PM I saw the comet in the binocular and at about 7:20PM I saw the comet with my naked eye.
Wednesday, October 2
Comet C/2023 A3 on morning October 2 by Kirk Severson. forum
Tuesday, October 1
Comet C/2023 A3 on morning October 1 by Josef Chlachula. forum
Comet C/2023 A3 Tsuchinshan-ATLAS from the access road to the Root River park at 6:01 CDT. Comet was not visible in binocular, but there is a tiny spot on this and more images. Moon crescent about 1d10h before New Moon. Bonus is asteroid Vesta with magnitude 8.1.
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