C/2023 A3 (Tsuchinshan-ATLAS): How To See It Tonight?
The best comet of 2024 is already visible in the sky! Right now, observers in the Southern Hemisphere are enjoying the brightening Comet C/2023 A3 (Tsuchinshan-ATLAS), and soon it will be visible in the Northern Hemisphere as well. Use the Star Walk 2 app to find out when and where to look for it from your location. Download the app now, and get ready to impress everyone with your stargazing skills when the comet shows up.
Contents
- What makes C/2023 A3 (Tsuchinshan-ATLAS) special?
- How to find C/2023 A3 (Tsuchinshan-ATLAS) in the sky?
- Is the comet C/2023 A3 (Tsuchinshan-ATLAS) visible now?
- Best time to observe C/2023 A3 (Tsuchinshan-ATLAS): how bright will it get? 🤩
- How to photograph Comet C/2023 A3 (Tsuchinshan-ATLAS)?
- Will C/2023 A3 (Tsuchinshan-ATLAS) become the next great comet?
- Discovery of C/2023 A3 (Tsuchinshan-ATLAS)
- Comet Tsuchinshan-ATLAS: Bottom line
“Comets are like cats: they have tails, and they do precisely what they want.”
― David H. Levy, Comets: Creators and Destroyers.
What makes C/2023 A3 (Tsuchinshan-ATLAS) special?
First of all, C/2023 A3 (Tsuchinshan-ATLAS) is likely to be very bright. The exact future brightness of this comet is unpredictable and depends heavily on its activity in the coming months. However, most sources agree on one thing: C/2023 A3 (Tsuchinshan-ATLAS) is likely to be visible to the naked eye. If we're lucky, it could become exceptionally bright and even outshine C/2020 F3 (NEOWISE) from summer 2020. It's been a long time since we've seen such a bright comet, so observers are very excited about C/2023 A3.
Also, C/2023 A3 (Tsuchinshan-ATLAS) is expected to grow a beautiful cometary tail. After passing by the Sun at a distance similar to Mercury's orbit, C/2023 A3's coma of dust and ice will heat up considerably. As the ice particles evaporate, they will quickly escape into space, taking with them a large amount of dust that will extend into a long, bright tail. As history shows, comets that pass close to the Sun have the most impressive tails, formed soon after being "roasted" by the Sun's heat. And this is the case with comet C/2023 A3!
In addition, C/2023 A3 (Tsuchinshan-ATLAS) will favor the Northern Hemisphere being perfectly visible there. The last time an exceptionally bright comet was visible from the northern latitudes was in 1997 when Comet Hale-Bopp lit up the sky.
How to find C/2023 A3 (Tsuchinshan-ATLAS) in the sky?
You can spot C/2023 A3 (Tsuchinshan-ATLAS) with Star Walk 2. Open the app and tap the magnifier icon at the bottom left of the screen. Then type “C/2023 A3” and tap the corresponding search result. The app will show you the comet’s current position in the sky for your location. Point your device at the sky and follow the white arrow to find the comet.
Is the comet C/2023 A3 (Tsuchinshan-ATLAS) visible now?
Comet C/2023 A3 (Tsuchinshan-ATLAS) is now visible in the Southern Hemisphere! You can see the comet in the morning, low in the eastern sky, just before sunrise. To get the best view, use binoculars with higher magnification, such as 10x50 or 12x50, which are preferable for comets low on the horizon.
The comet has a magnitude of about 4.7, which is brighter than expected, and it is getting brighter each day. Remember, comets can be seen with the naked eye when they reach a magnitude of about 4 in a dark sky.
Even though the comet is close to the Sun (with an elongation of ≤23°), many observers manage to see the comet even under difficult conditions. Every day, new images of C/2023 A3 appear on the Internet.
In the Northern Hemisphere, the comet is closer to the horizon and hard to see because of the Sun’s brightness. It will become visible in northern latitudes in early October.
C/2023 A3 (Tsuchinshan-ATLAS) visibility forecast for 2024
Here are the predictions for the visibility of C/2023 A3 (Tsuchinshan-ATLAS) in the coming weeks:
-
September 18-26: from 4.7 to 3.0 mag, appears in the morning sky in the Southern Hemisphere, low above the eastern horizon in the constellation of Sextans. Requires binoculars (preferably 10x50 or 12x50). Good time to observe the cometary tail (possibly double tail).
-
September 27-October 2: from 3.0 to 0.0 mag, reaches the closest point to the Sun (perihelion) on September 27, appearing in the morning sky in the Southern Hemisphere and in the Northern Hemisphere (below 40°N). Passes from the constellation of Sextans into the constellation of Leo on September 28. May be visible to the naked eye.
-
October 2-9: from 0.0 to -3.0 mag, but too close to the Sun to be visible to the naked eye. Can be observed and photographed with a telescope in the morning with the necessary precautions. The most optimistic forecasts say that the comet will exceed magnitude -5.0 — if so, it'll be visible to the naked eye even in the daytime sky close to the Sun.
-
October 10-12: from -3.0 to -1.0 mag, appears in the evening in the Northern Hemisphere shortly after sunset, very low in the western sky in the constellation of Virgo. Short observation window, but visible with the naked eye! Best time to see the comet. Makes its closest approach to Earth on October 12.
-
October 13-14: from -1.0 to 1.0 mag, quickly losing brightness, but moving farther from the Sun and therefore easier to see. Visible with the naked eye in the evening about an hour after sunset. On October 14, C/2023 A3 will pass close to another comet, 13P/Olbers (mag 10).
-
October 15-19: 1.0 to 4.5 mag, moving toward Serpens Caput. May produce an anti-tail — a bright streak that appears to be pointing toward the Sun, opposite the other tails. On October 15, it will pass 1.4° from the M5 globular cluster, providing a good photo opportunity.
-
October 20-31: 4.5 to 7.0 mag, moving across the constellation Ophiuchus relatively high in the southwestern sky in the evening. Visible with binoculars and telescopes. During these days, the tail of the comet will begin to grow rapidly, possibly reaching up to 20° long (about 40 times the size of the Full Moon) under dark skies.
-
November: from 7 to 8 mag, visible in the evening. Rises higher in the Northern Hemisphere after sunset.
-
December: from 8 to 10 mag, gradually moves closer to the Sun in our sky, rising lower above the horizon. Not visible from the Southern Hemisphere.
Remember that comets become visible to the naked eye at around magnitude 4. The magnitude scale measures the total light spread over the object, so the naked-eye visibility limit is lower (mag 6.5) for pinpoint sources of light, like stars or planets, and higher for diffuse objects, like comets or galaxies.
Please note that comets are very unpredictable space objects, and data (especially apparent magnitude) can change quickly. However, we’ll do our best to keep you up to date.
C/2023 A3 (Tsuchinshan-ATLAS) approaching the Earth in 2024: path through the Solar System
Here, you can get a month-by-month guide on the comet’s journey through the Solar System in 2024. We also made a video to visualize the comet's trajectory in space. Watch it to see how the comet's brightness and location will change over time.
-
September: comet C/2023 A3 will enter Venus’s orbit. On September 27, the comet will pass perihelion, meaning it will come the closest to the Sun, at a distance of 0.39 AU. During this period, the comet may break apart under the impact of the high temperature.
-
October: if C/2023 A3 survives perihelion, then on October 12, it will come the closest to the Earth and will be at a distance of 0.48 AU from our planet. It will reach maximum brightness and be observable even with the naked eye.
-
November: C/2023 A3 will gradually lose its brightness as it will move away from the Earth. By the end of the month, the distance between the comet and our planet will increase to 1.94 AU. For the next 20 years the comet will be moving toward the edge of the Solar System and will not return for another 26,000 years.
Best time to observe C/2023 A3 (Tsuchinshan-ATLAS): how bright will it get? 🤩
Comet C/2023 A3 (Tsuchinshan-ATLAS) will reach its peak brightness around October 12, when it will pass at its closest distance to the Earth (0.48 AU). It's hard to predict the exact brightness of the comet — most tend to think it will be bright enough to be visible to the naked eye.
On October 9-12, due to the effect of forward scattering, C/2023 A3 might brighten up to -4.0 magnitude! By comparison, the comet Hale-Bopp, one of the most widely observed comets of the 20th century, had a peak magnitude of -1.8. The so-called green comet C/2022 E3 (ZTF), which was trending at the beginning of 2023, reached a maximum magnitude of 5.4. The famous NEOWISE (C/2020 F3) peaked at 0.9.
To extend the show, start looking for the comet in the morning sky at the end of September. It will be visible very low in the sky before sunrise. On September 27, C/2023 A3 (Tsuchinshan-ATLAS) will make its closest approach to the Sun (0.39 AU). At best, C/2023 A3 will have a magnitude of -1 at this time; at worst, it will have a magnitude of 4 (barely visible to the naked eye under very dark skies).
After the perihelion, C/2023 A3 (Tsuchinshan-ATLAS) will disappear for a while and reappear in the evening sky in early October 2024. It will remain an evening object until the end of the month. However, after October 12, the comet will fade out rapidly and won’t be visible to the naked eye by the end of the month.
How to photograph Comet C/2023 A3 (Tsuchinshan-ATLAS)?
Aim to photograph C/2023 A3 between October 11 and 15 in the evening as soon as you spot the comet. To photograph the comet, you'll need:
- DSLR or mirrorless camera;
- Sturdy tripod;
- Wide-angle or zoom lens.
-
Camera setup: Use manual mode to control settings. Set ISO between 400 and 800 depending on the comet's brightness. Use a wide aperture (f/2.8–f/4) for more light.
-
Focus: Manually focus on a bright star or the Moon.
-
Exposure: Set exposure time between 10 to 30 seconds to avoid star trailing.
-
Location: Choose a dark site with minimal light pollution. Use apps like Star Walk 2 or Sky Tonight to track the comet’s location.
-
Image stacking: For better detail, take multiple shots and stack them using programs like DeepSkyStacker or RegiStax. Stacking can enhance the comet’s tail and reduce noise.
-
Post-processing: Use editing software like Photoshop to adjust brightness, contrast, and sharpness for a polished final image.
Bonus tip: Do some research on what settings and equipment other astrophotographers are using to capture comet shots. The Comet Watch Facebook group is a great resource where you can ask questions, learn from experienced photographers, and find plenty of useful information.
Will C/2023 A3 (Tsuchinshan-ATLAS) become the next great comet?
C/2023 A3 (Tsuchinshan-ATLAS) may well be the next great comet. Although there is no official definition of the term, great comets are usually exceptionally bright. So bright, in fact, that even a casual observer who isn't intentionally looking for a comet will notice it. Such comets also become well-known outside the astronomical community. The comets Hale-Bopp in 1997 and McNaught in 2007 were among the last comets to be called great. Again, comets are very unpredictable bodies, and there is always room for a surprise. For now, all we have to do is wait patiently for C/2023 A3's performance in autumn 2024.
Discovery of C/2023 A3 (Tsuchinshan-ATLAS)
On February 22, 2023, the ATLAS telescope in South Africa detected a new faint object that was proven to be a comet. It was temporarily designated as A10SVYR. The comet was also independently captured by a telescope at Purple Mountain Observatory (Zijinshan Astronomical Observatory) on January 9, 2023. It was added to the list of objects awaiting confirmation, but after no follow-up observations were reported, it was removed on January 30, 2023, and was considered lost. Based on the comet naming system, the comet received the names of both observatories and was officially named C/2023 A3 (Tsuchinshan-ATLAS).
Shortly after its discovery, observations up to April 2022 were found in the archives of the Minor Planet Center. C/2023 A3 (Tsuchinshan-ATLAS) is a long-period comet that completes one orbit around the Sun in 80,660 years.
Meaning of the comet C/2023 A3 (Tsuchinshan-ATLAS) name
The name of the comet contains data about where and when the comet was first seen:
- The letter C indicates a non-periodic comet – comets of this type originate from the Oort cloud and may pass through the Solar System only once or take from 200 to thousands of years to orbit the Sun;
- 2023 A3 means the comet was discovered in 2023, in the first half of January (this corresponds to the letter A in the IAU comet naming system), and was the third such object discovered in the same period;
- Tsuchinshan-ATLAS means the discovery was made using telescopes of the Purple Mountain Observatory (Zijinshan Astronomical Observatory) and Asteroid Terrestrial-impact Last Alert System (ATLAS).
Comet Tsuchinshan-ATLAS: Bottom line
Comet C/2023 A3 (Tsuchinshan-ATLAS) is already visible with binoculars from the Southern Hemisphere and will soon be visible from the Northern Hemisphere. Around October 12, 2024, it could reach magnitude -4 and become one of the brightest comets visible in the Northern Hemisphere in the last 100 years! Use the Star Walk 2 app to locate C/2023 A3 (Tsuchinshan-ATLAS) in the sky. The app's Time Machine feature will allow you to see the comet's position in your sky in the future. Watch our video tutorial to learn how to use this feature.
