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Comet C/2023 A3 (Tsuchinshan-ATLAS)

Below the horizon.  Rise: 3:52 | Tran: 10:46 | Set: 17:41
Alt: -26.38°   Az: 344.84°   Direction: North-North-West

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.

Comet C/2023 A3 (Tsuchinshan-ATLAS) is in the constellation of Aquila, at a distance of 502,873,812.0 kilometers from Earth. The current Right Ascension is 20h 14m 01s and the Declination is +11° 00’ 00” (apparent coordinates). The latest observed magnitude of Comet C/2023 A3 (Tsuchinshan-ATLAS) is 11.7 (data provided by COBS).

Finder Charts

Map showing Comet C/2023 A3 (Tsuchinshan-ATLAS) in Aquila on February, 11 2025. Field of view: 50x30 degrees
View interactive star map
Sky map showing Comet C/2023 A3 (Tsuchinshan-ATLAS) in Aquila on February, 11 2025. Field of view: 15x9 degrees. View in interactive sky chart

High precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2023 A3 (Tsuchinshan-ATLAS) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2023 A3 (Tsuchinshan-ATLAS)
RA: 20h 12m 49s
Dec: +10° 55’ 23”
Deep sky finder chart for Comet C/2023 A3 (Tsuchinshan-ATLAS). Field of view: 60x40 arcmins. View in deep sky object tracker

Also check out Where is Comet C/2023 A3 (Tsuchinshan-ATLAS)?, a page that provides all the information needed to find Comet C/2023 A3 (Tsuchinshan-ATLAS) in the sky and additional links to sky charts.

Celestial Coordinates

Apparent

20h 14m 01s
+11° 00’ 00”
11h 04m 46s
07h 18m 47s

J2000

20h 12m 49s
+10° 55’ 23”

Additional Information

Aquila
11.7
1.5'
7.0'
2025-02-08
13.50

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

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):

Azimuth: 79.1°
Max altitude: 49.5°
Azimuth: 281.0°
  • C/2023 A3 (Tsuchinshan-ATLAS) is below the horizon from Greenwich, UK.
  • Given its current magnitude, C/2023 A3 (Tsuchinshan-ATLAS) is visible with the help of a telescope having an aperture of 8 inches (200mm) or more.
  • Go to interactive sky chart

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 502,873,812.0 kilometers, equivalent to 3.3615038078 Astronomical Units. Light takes 27m 57.406s to travel from Comet C/2023 A3 (Tsuchinshan-ATLAS) and arrive to us.

502,873,812.0
3.3615038078
27m 57.406s

The following chart shows the distance of Comet C/2023 A3 (Tsuchinshan-ATLAS) from Earth as a function of time. In the chart the distance data is measured in Astronomical Units and sampled with an interval of 1 day.

Chart of the distance of Comet C/2023 A3 (Tsuchinshan-ATLAS) from Earth in Astronomical Units (au)

The value of the reported distance might be somewhat inaccurate around the times of closest approach for objects passing extremely close to Earth. 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 and Data Tracker.

Closest Approach

Between 1 January 2000 and 31 December 2099, the closest approach of Comet C/2023 A3 (Tsuchinshan-ATLAS) to Earth happens on Sun Oct 13 2024 at a distance of 0.472744 Astronomical Units, or 70,721,499 kilometers:

Sun Oct 13 2024
70,721,499
0.472744

NOTE: values for the closest approach are computed with a sampling interval of 1 day.

Light Curve

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet C/2023 A3 (Tsuchinshan-ATLAS), according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.

Chart of the magnitude of Comet C/2023 A3 (Tsuchinshan-ATLAS) as a function of time

Orbital Elements

The following table lists the orbital elements of Comet C/2023 A3 (Tsuchinshan-ATLAS) at epoch 24 January 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 2024-Sep-27 17:38:45
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

Orbit Diagram of Comet C/2023 A3 (Tsuchinshan-ATLAS)
View Comet C/2023 A3 (Tsuchinshan-ATLAS) in the 3D Solar System Simulator

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
2025 Feb 04 20h 09m 18s +09° 57’ 35” 13.35 Aquila
2025 Feb 05 20h 09m 56s +10° 05’ 13” 13.37 Aquila
2025 Feb 06 20h 10m 33s +10° 12’ 57” 13.39 Aquila
2025 Feb 07 20h 11m 10s +10° 20’ 44” 13.41 Aquila
2025 Feb 08 20h 11m 46s +10° 28’ 36” 13.43 Aquila
2025 Feb 09 20h 12m 21s +10° 36’ 31” 13.45 Aquila
2025 Feb 10 20h 12m 56s +10° 44’ 31” 13.46 Aquila
2025 Feb 11 20h 13m 30s +10° 52’ 36” 13.48 Aquila
2025 Feb 12 20h 14m 04s +11° 00’ 44” 13.50 Aquila
2025 Feb 13 20h 14m 37s +11° 08’ 56” 13.52 Aquila
2025 Feb 14 20h 15m 10s +11° 17’ 13” 13.53 Aquila
2025 Feb 15 20h 15m 42s +11° 25’ 34” 13.55 Delphinus
2025 Feb 16 20h 16m 14s +11° 33’ 59” 13.57 Delphinus
2025 Feb 17 20h 16m 44s +11° 42’ 28” 13.58 Delphinus

Additional Resources