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🌎  Observing from: Greenwich, United Kingdom [change]
🌅 Sunrise: 6:45  ☀️ Transit: 13:03  🌅 Sunset: 19:23

Comet C/2021 C3 (Catalina)

Comet C/2021 C3 (Catalina) is currently in the constellation of Cassiopeia. The current Right Ascension of Comet C/2021 C3 (Catalina) is 01h 16m 06s and the Declination is +60° 59’ 08” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2021 C3 (Catalina) is 24.54 (JPL).

01h 16m 06s
+60° 59’ 08”

Today's rise, transit and set times of Comet C/2021 C3 (Catalina) from Greenwich, United Kingdom [change] (all times relative to the local timezone Europe/London):

Today Comet C/2021 C3 (Catalina) is circumpolar and transits at 12:53 UTC reaching a maximum altitude of 80.5°.
  • C/2021 C3 (Catalina) is above the horizon from Greenwich, United Kingdom [change].
  • Right now it is placed in the North-West direction at an altitude of 43° above the horizon.
  • Given its current magnitude, C/2021 C3 (Catalina) is visible only through long exposure photography.
  • 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.

Available Resources

Comet C/2021 C3 (Catalina) Position and Finder Charts

Below we provide Comet C/2021 C3 (Catalina) finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.

Map showing Comet C/2021 C3 (Catalina) in Cassiopeia on March, 28 2023
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2021 C3 (Catalina) in Cassiopeia on March, 28 2023
Field of view: 10x6 degrees
View fullscreen
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Higher precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2021 C3 (Catalina) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2021 C3 (Catalina)
RA: 01h 16m 06s
Dec: +60° 59’ 08”
Deep sky finder chart for Comet C/2021 C3 (Catalina)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2021 C3 (Catalina)?, a page that provides all the information needed to find Comet C/2021 C3 (Catalina) in the sky and additional links to sky charts.

Comet C/2021 C3 (Catalina) Distance from Earth

The distance of Comet C/2021 C3 (Catalina) from Earth is currently 1,189,865,432 kilometers, equivalent to 7.953759 Astronomical Units. Light takes 1 hours, 6 minutes and 8.9639 seconds to travel from Comet C/2021 C3 (Catalina) and arrive to us.

1 hours, 6 minutes and 8.9639 seconds

The following chart shows the distance of Comet C/2021 C3 (Catalina) 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/2021 C3 (Catalina) 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/2021 C3 (Catalina) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest Approach of Comet C/2021 C3 (Catalina) to Earth

Between 1 January 2013 and 30 December 2100, the closest approach of Comet C/2021 C3 (Catalina) to Earth happens on Sun Mar 14 2021 at a distance of 1.325110 Astronomical Units, or 198,233,576 kilometers:

Sun Mar 14 2021

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

Comet C/2021 C3 (Catalina) Brightness

The current visual magnitude of Comet C/2021 C3 (Catalina) is 24.54.


The observed magnitude and coma diameter values are derived from the Comet Observers Database by averaging the values reported in recent observations (more recent than 4 days), when available. The Estimated Magnitude comes from the JPL Horizons ephemerides service and might be inaccurate given the highly dynamic and unpredictable behavior of comets. When available, please refer to the Observed Magnitude value and consider the Estimated 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.

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet C/2021 C3 (Catalina), 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/2021 C3 (Catalina) as a function of time

Comet C/2021 C3 (Catalina) Orbital Elements

The following table lists the orbital elements of Comet C/2021 C3 (Catalina) at epoch 14 March 2021 00:00 UTC (JD: 2459288.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.96404857
Orbit inclination i 122.16139874°
Perihelion distance q 2.27650136 AU
340,559,757 km
Aphelion distance Q 124.36664993 AU
18,604,986,052 km
Semi-major axis a 63.32157564 AU
9,472,772,905 km
Orbital period period 503.8900 years
184,045.8361 days
Date of perihelion transit Tp 2021-Feb-12 10:39:06
2,459,257.9438 JD
Next perihelion transit 2525-Jan-07 06:43
2,643,303.7799 JD
Argument of perihelion peri 357.15183716204°
Longitude of the ascending node node 181.91977801275°
Mean anomaly M 0.059768928115345°
Mean motion n 0.00195603°/day

Visualization of Comet C/2021 C3 (Catalina) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2021 C3 (Catalina) with respect of the Sun and the orbits of the major planets. The position of Comet C/2021 C3 (Catalina) and the planets along their orbits in this diagram accurately represents the current configuration of the objects in the Solar System. This is an experimental feature and it requires a WebGL enabled browser. Please provide us feedback!

Orbit Diagram of Comet C/2021 C3 (Catalina)
View Comet C/2021 C3 (Catalina) in the 3D Solar System Simulator

Comet C/2021 C3 (Catalina) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2021 C3 (Catalina) computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet C/2021 C3 (Catalina) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2023 Mar 21 01h 09m 33s +61° 13’ 09” 24.49 Cassiopeia
2023 Mar 22 01h 10m 23s +61° 11’ 00” 24.50 Cassiopeia
2023 Mar 23 01h 11m 15s +61° 08’ 59” 24.50 Cassiopeia
2023 Mar 24 01h 12m 05s +61° 07’ 04” 24.51 Cassiopeia
2023 Mar 25 01h 12m 55s +61° 05’ 13” 24.51 Cassiopeia
2023 Mar 26 01h 13m 45s +61° 03’ 29” 24.52 Cassiopeia
2023 Mar 27 01h 14m 35s +61° 01’ 51” 24.53 Cassiopeia
2023 Mar 28 01h 15m 25s +61° 00’ 19” 24.53 Cassiopeia
2023 Mar 29 01h 16m 17s +60° 58’ 50” 24.54 Cassiopeia
2023 Mar 30 01h 17m 07s +60° 57’ 29” 24.54 Cassiopeia
2023 Mar 31 01h 17m 57s +60° 56’ 12” 24.55 Cassiopeia
2023 Apr 01 01h 18m 47s +60° 55’ 01” 24.56 Cassiopeia
2023 Apr 02 01h 19m 36s +60° 53’ 57” 24.56 Cassiopeia
2023 Apr 03 01h 20m 26s +60° 52’ 57” 24.57 Cassiopeia