Comet C/2023 A3 (Tsuchinshan-ATLAS) was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on 22 February 2023 and it was also independently observed few weeks before in January 2023 at the Tsuchinshan Chinese Observatory (Purple Mountain Observatory of the Chinese Academy of Sciences). The official designation includes both Tsuchinshan and ATLAS due to these independent observations. Its retrograde orbit, meaning it moves in the opposite direction to most major solar system objects, is parabolic-like with a perihelion distance of 0.39 astronomical units (AU). Comet C/2023 A3 (Tsuchinshan-ATLAS) is notable and actively observed because, based on current estimations, it is could become bright enough to be visible to the naked eye during its perihelion passage between September and October 2024.
Find it in the Sky
Chose a date & time and view the position of comet C/2023 A3 (Tsuchinshan-ATLAS) in the sky on our interactive planetarium.
In Evidence
Comet C/2023 A3 (Tsuchinshan-ATLAS)
Comet C/2023 A3 (Tsuchinshan-ATLAS) is in the constellation of Lyra, at a distance of
Finder Charts
The sky charts below show, at different resolutions, the position of comet C/2023 A3 (Tsuchinshan-ATLAS) in the sky. Click on each chart to access the interactive star map tool.
The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of comet C/2023 A3 (Tsuchinshan-ATLAS) against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.
Equatorial Coordinates
Apparent
J2000
Additional Information
The observed values of Magnitude, Coma Diameter and Tail Length are derived from the most recent observation recorded at the Comet Observers Database. The value of Predicted Magnitude comes from the JPL Horizons ephemerides service and, in the case of comets, might be inaccurate given the highly dynamic and unpredictable behavior of these objects. When available, please refer to the Observed Magnitude value and consider the Predicted Magnitude as a directional indication. We acknowledge with thanks the comet observations from the COBS Comet Observation Database contributed by observers worldwide and used in this table to report recent comet observations.
Rise and Set Times
The following table lists today's rise, transit and set times of comet C/2023 A3 (Tsuchinshan-ATLAS) from Greenwich, UK (all times relative to the local timezone Europe/London):
If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.
Distance from Earth
The distance of comet C/2023 A3 (Tsuchinshan-ATLAS) from Earth is currently
The following graph shows the distance of comet C/2023 A3 (Tsuchinshan-ATLAS) from Earth as a function of time. In the chart the distance is measured in Astronomical Units and the data is sampled with an interval of 1 day.
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).
The value of the distance of C/2023 A3 (Tsuchinshan-ATLAS) from Earth is also available as a real time updated value in the live position tracker.
Closest Approach to Earth
In the period between January 1, 2000 and December 31, 2099, the closest approach of comet C/2023 A3 (Tsuchinshan-ATLAS) to Earth happened on Sunday 13 October 2024 at a distance of 0.472744 Astronomical Units, or 70,721,499 kilometers:
Note: the values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
The following chart shows the light curve of comet C/2023 A3 (Tsuchinshan-ATLAS), i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.
Orbital Elements
The following table lists the orbital elements of comet C/2023 A3 (Tsuchinshan-ATLAS) at epoch January, 24 2024 00:00 UTC (JD: 2460334.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 1.00012475 |
| Orbit inclination | i | 139.11502467° |
| Perihelion distance | q | 0.39145906 AU 58,561,442 km |
| Aphelion distance | Q | n.a. |
| Semi-major axis | a | n.a. |
| Orbital period | period | n.a. |
| Date of perihelion transit | Tp | September 27, 2024 2,460,581.2353 JD |
| Argument of perihelion | peri | 308.4872848828° |
| Longitude of the ascending node | node | 21.558609111275° |
| Mean anomaly | M | -0.0013834563352416° |
| Mean motion | n | 0.00000561°/day |
Orbit Visualization
The following chart is a 3D animated visualization of the orbit of comet C/2023 A3 (Tsuchinshan-ATLAS) relative to the other major objects in the Solar System. You can access more advanced features using our 3D Solar System Viewer.
15 Days Ephemeris
The following table lists the ephemerides of comet C/2023 A3 (Tsuchinshan-ATLAS) computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.
| Date | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Constellation |
|---|---|---|---|---|
| Jul 10 2025 | 18h 46m 23s | +28° 19’ 38” | 14.80 | Lyra |
| Jul 11 2025 | 18h 45m 00s | +28° 14’ 43” | 14.82 | Lyra |
| Jul 12 2025 | 18h 43m 38s | +28° 09’ 36” | 14.83 | Lyra |
| Jul 13 2025 | 18h 42m 16s | +28° 04’ 15” | 14.84 | Lyra |
| Jul 14 2025 | 18h 40m 56s | +27° 58’ 42” | 14.85 | Lyra |
| Jul 15 2025 | 18h 39m 36s | +27° 52’ 57” | 14.86 | Lyra |
| Jul 16 2025 | 18h 38m 17s | +27° 46’ 59” | 14.88 | Lyra |
| Jul 17 2025 | 18h 36m 59s | +27° 40’ 50” | 14.89 | Lyra |
| Jul 18 2025 | 18h 35m 43s | +27° 34’ 30” | 14.90 | Lyra |
| Jul 19 2025 | 18h 34m 27s | +27° 27’ 58” | 14.91 | Lyra |
| Jul 20 2025 | 18h 33m 12s | +27° 21’ 16” | 14.93 | Lyra |
| Jul 21 2025 | 18h 31m 59s | +27° 14’ 23” | 14.94 | Lyra |
| Jul 22 2025 | 18h 30m 47s | +27° 07’ 20” | 14.95 | Lyra |
| Jul 23 2025 | 18h 29m 35s | +27° 00’ 07” | 14.97 | Lyra |
Additional Resources on TheSkyLive
- Comet C/2023 A3 (Tsuchinshan-ATLAS): Complete reference information on TheSkyLive.com.
- Where is comet C/2023 A3 (Tsuchinshan-ATLAS)?: Key information on where to find comet C/2023 A3 (Tsuchinshan-ATLAS) in the sky.
- Distance of comet C/2023 A3 (Tsuchinshan-ATLAS) from Earth: Find out how far comet C/2023 A3 (Tsuchinshan-ATLAS) is from Earth right now.
- How Bright is comet C/2023 A3 (Tsuchinshan-ATLAS)?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Rise and set times of comet C/2023 A3 (Tsuchinshan-ATLAS) from your location.
- Interactive Sky Map: Planetarium-style interactive visualization of comet C/2023 A3 (Tsuchinshan-ATLAS)'s position in the sky.
- Live Position Tracker: High precision real time tracker of comet C/2023 A3 (Tsuchinshan-ATLAS)'s position using deep space imagery.
- Ephemeris: 15 days comet C/2023 A3 (Tsuchinshan-ATLAS)'s computed ephemeris.
- Orbital elements: Information about comet C/2023 A3 (Tsuchinshan-ATLAS) orbital parameters.
- Orbit Visualization: 3D interactive visualization showing the orbit of comet C/2023 A3 (Tsuchinshan-ATLAS) with respect to the major Solar System objects.