C/2023 A3 (Tsuchinshan-ATLAS): How and Where to See It Tonight?
Catch the Comet This Week! Comet C/2023 A3 (Tsuchinshan-ATLAS) is on its way, and it’s your chance to see the brightest comet in over a decade! This week, October 14-20, look up to catch this amazing sight. Not sure where to look? No problem! Just download the Star Walk 2 app, and we'll guide you directly to the comet. Curious for more cool facts and viewing tips? Check out our full article for all the details. Join millions who’ll be watching this spectacular comet. Get the app now, read on, and prepare to be amazed!
Contents
- What makes C/2023 A3 (Tsuchinshan-ATLAS) special?
- Tsuchinshan-ATLAS Tracker: how to find C/2023 A3 in the sky
- Where to see the comet C/2023 A3 (Tsuchinshan-ATLAS) now?
- Best time to observe C/2023 A3 (Tsuchinshan-ATLAS): how bright will it get? 🤩
- How to photograph Comet C/2023 A3 (Tsuchinshan-ATLAS)?
- Is C/2023 A3 (Tsuchinshan-ATLAS) a 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 the brightest comet in the last 13 years and visible to the naked eye! On October 2, it reached a magnitude of 0.4, overtaking the famous C/2020 F3 (NEOWISE) (peak magnitude 0.9) from summer 2020. From around October 11, Comet Tsuchinshan-ATLAS is visible to the naked eye from the Northern Hemisphere — hundreds of observers have already reported their naked-eye observations.
Also, C/2023 A3 (Tsuchinshan-ATLAS) has grown a beautiful long cometary tail. It's already 21° long — about 42 times the size of the Full Moon's disk. After passing the Sun at a distance similar to Mercury's orbit, C/2023 A3's coma of dust and ice has heated up considerably. As the ice particles evaporate, they quickly escape into space, taking with them a large amount of dust that will extend into a long, bright tail. History shows that comets that pass close to the Sun have the most impressive tails, formed soon after being "roasted" by the Sun's heat. This is the case with comet C/2023 A3!
In addition, in the middle of October, 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.
Bonus: Comet Tsuchinshan-ATLAS has temporarily turned into a unicorn! For a while, it showed a thin streak of light opposite its dust tail, resembling a unicorn’s horn. In astronomy, this phenomenon is known as an anti-tail. It forms from the largest and heaviest dust particles, which the solar wind struggles to push away, so they appear behind the comet as seen from Earth. The anti-tail becomes visible only when Earth is crossing the comet’s orbital plane, which occurred from October 13 to 15.
Tsuchinshan-ATLAS Tracker: how to find C/2023 A3 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.
Where to see the comet C/2023 A3 (Tsuchinshan-ATLAS) now?
Comet C/2023 A3 (Tsuchinshan-ATLAS) is now well visible low above the western horizon just after sunset for observers in the Northern Hemisphere. While the comet is still close to the Sun, it will gradually move farther away throughout the week, making it easier to spot. Although it will lose brightness, your chances of seeing the comet will improve! It’s visible to the naked eye, but a pair of 10x50 binoculars will give you an even better view.
In the Southern Hemisphere, the comet remains closer to the Sun, but visibility will improve with each passing day. Around October 16, observers in southern latitudes should be able to see Comet Tsuchinshan-ATLAS as its apparent distance from the Sun will increase. Don’t miss this opportunity!
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. The lower the magnitude, the brighter the comet appears! The brightest objects have negative magnitude values.
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October 14-20: from 0.5 to 1.7 mag, 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. You can see an anti-tail — a bright streak that appears to be pointing toward the Sun, opposite the other tails. On October 15, the comet will pass 1.4° from the M5 globular cluster, providing a good photo opportunity. Passes through the Serpens Caput constellation.
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October 20-31: from 1.9 to 3.9 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 might grow rapidly.
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November: from 4 to 8 mag, visible in the evening. Rises higher in the Northern Hemisphere after sunset.
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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.
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October: on October 12, C/2023 A3 passed the closest point to the Earth and was at a distance of 0.47 AU (71 million km or 44 million miles) from our planet. This is when the comet reached its maximum brightness and became visible to the naked eye.
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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) reached its peak brightness on October 12, during its closest approach to Earth (0.47 AU). The comet reached a negative magnitude, making it visible to the naked eye. But the excitement isn’t over yet!
Even though C/2023 A3 is now moving away from the Sun, it remains visible to the naked eye. From October 14 to October 20, you’ll still have a great chance to spot this comet, which continues to shine much brighter than any other comet in 2024. According to COBS, Comet Tsuchinshan-ATLAS will maintain a brightness between magnitude 0.5 and 1.7 throughout the week — about as bright as the famous Comet NEOWISE (C/2020 F3) at its peak in summer 2020. Don't miss the chance to see and photograph C/2023 A3, which has become one of the most photographed comets of this century!
To track the exact position of Comet Tsuchinshan-ATLAS from your location, use the Star Walk 2 astronomy app. The app provides a personalized sky map for your site. You can also use the Time Machine feature (located in the upper right corner) to visualize the comet’s position at different times. Don’t miss out on capturing this rare celestial event!
How to photograph Comet C/2023 A3 (Tsuchinshan-ATLAS)?
Aim to photograph C/2023 A3 between October 9 and 15 in the evening as soon as you spot the comet. To photograph the comet, you'll need:
- DSLR, mirrorless camera, or smartphone (preferably with advanced night mode settings);
- Sturdy tripod;
- Wide-angle or zoom lens.
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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.
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Focus: Manually focus on a bright star or the Moon.
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Exposure: Set exposure time between 10 to 30 seconds to avoid star trailing.
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Location: Choose a dark site with minimal light pollution. Use apps like Star Walk 2 or Sky Tonight to track the comet’s location.
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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.
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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.
Is C/2023 A3 (Tsuchinshan-ATLAS) a great comet?
While there's no strict definition for a "great comet", they’re 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.
So, did C/2023 A3 (Tsuchinshan-ATLAS) achieve such fame? It certainly has made headlines around the world. As for its brightness, while it’s the brightest comet we've seen in the past decade, it didn’t quite reach the dazzling brilliance of Comet Hale-Bopp in 1997. Ultimately, the astronomical community will decide if Comet Tsuchinshan-ATLAS earns the title of a "great comet."
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) put on a great show on October 12, becoming visible to the naked eye — and it’s not done yet! This week is a perfect time to spot C/2023 A3 as it moves away from the Sun, making it even easier to see. 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.
October 2024 has another big comet for us — if it survives, this brand-new guest may outshine Venus at the end of the month! Learn more about C/2024 S1 (ATLAS) in the dedicated article.
