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🌎  Greenwich, United Kingdom [change]

Comet C/2021 A4 (NEOWISE)

Comet C/2021 A4 (NEOWISE) is currently in the constellation of Grus. The current Right Ascension of Comet C/2021 A4 (NEOWISE) is 22h 47m 57s and the Declination is -39° 21’ 07” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2021 A4 (NEOWISE) is 38.29 (JPL).

Summary of key facts about Comet C/2021 A4 (NEOWISE) [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:

22h 47m 57s
-39° 21’ 07”

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.

Additional information about Comet C/2021 A4 (NEOWISE) available on TheSkyLive:

Available Resources

Comet C/2021 A4 (NEOWISE) Position and Finder Charts

Below we provide Comet C/2021 A4 (NEOWISE) 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 A4 (NEOWISE) in Grus on June, 26 2022
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2021 A4 (NEOWISE) in Grus on June, 26 2022
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 A4 (NEOWISE) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2021 A4 (NEOWISE)
RA: 22h 47m 57s
Dec: -39° 21’ 07”
Deep sky finder chart for Comet C/2021 A4 (NEOWISE)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2021 A4 (NEOWISE)?, a page that provides all the information needed to find Comet C/2021 A4 (NEOWISE) in the sky and additional links to sky charts.

Comet C/2021 A4 (NEOWISE) Distance from Earth

The distance of Comet C/2021 A4 (NEOWISE) from Earth is currently 740,098,178 kilometers, equivalent to 4.947251 Astronomical Units. Light takes 41 minutes and 8.7018 seconds to travel from Comet C/2021 A4 (NEOWISE) and arrive to us.

41 minutes and 8.7018 seconds

The following chart shows the distance of Comet C/2021 A4 (NEOWISE) 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.

Distance of Comet C/2021 A4 (NEOWISE) from Earth between January 2013 and December 2100

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 A4 (NEOWISE) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet C/2021 A4 (NEOWISE) to Earth

Between January 2013 and December 2100, the closest approach of Comet C/2021 A4 (NEOWISE) to Earth happens on Fri Feb 12 2021 at a distance of 0.433930 Astronomical Units, or 64,915,004 kilometers:

Fri Feb 12 2021

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

Comet C/2021 A4 (NEOWISE) brightness

The current visual magnitude of Comet C/2021 A4 (NEOWISE) is 38.29.


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 A4 (NEOWISE), 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.

Predicted magnitude of Comet C/2021 A4 (NEOWISE) between January 2013 and December 2100

Comet C/2021 A4 (NEOWISE) rise and set times

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Comet C/2021 A4 (NEOWISE) is currently not visible from Greenwich, United Kingdom [change]

The rise and set times are defined as the time at which the upper limb of Comet C/2021 A4 (NEOWISE) touches the horizon, considering the effect of the atmospheric refraction. As the atmospheric conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.

Comet C/2021 A4 (NEOWISE) Orbital Elements

The following table lists the orbital elements of Comet C/2021 A4 (NEOWISE) at epoch 15 February 2021 00:00 UTC (JD: 2459261.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.97324748
Orbit inclination i 111.56983372°
Perihelion distance q 1.14547639 AU
171,360,829 km
Aphelion distance Q 84.48956049 AU
12,639,458,371 km
Semi-major axis a 42.81751844 AU
6,405,409,600 km
Orbital period period 280.1821 years
102,336.5253 days
Date of perihelion transit Tp 2021-Mar-20 00:53:23
2,459,293.5371 JD
Next perihelion transit 2301-May-28 13:29
2,561,630.0624 JD
Argument of perihelion peri 204.66556616438°
Longitude of the ascending node node 307.08476248258°
Mean anomaly M 359.8872997811°
Mean motion n 0.00351781°/day

Visualization of Comet C/2021 A4 (NEOWISE) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2021 A4 (NEOWISE) with respect of the Sun and the orbits of the major planets. The position of Comet C/2021 A4 (NEOWISE) 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 A4 (NEOWISE)
View Comet C/2021 A4 (NEOWISE) in the 3D Solar System Simulator

Comet C/2021 A4 (NEOWISE) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2021 A4 (NEOWISE) 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 A4 (NEOWISE) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2022 Jun 19 22h 52m 45s -38° 40’ 06” 38.16 Grus
2022 Jun 20 22h 52m 12s -38° 45’ 20” 38.17 Grus
2022 Jun 21 22h 51m 37s -38° 50’ 35” 38.19 Grus
2022 Jun 22 22h 51m 01s -38° 55’ 51” 38.21 Grus
2022 Jun 23 22h 50m 23s -39° 01’ 09” 38.23 Grus
2022 Jun 24 22h 49m 45s -39° 06’ 29” 38.25 Grus
2022 Jun 25 22h 49m 06s -39° 11’ 49” 38.26 Grus
2022 Jun 26 22h 48m 27s -39° 17’ 12” 38.28 Grus
2022 Jun 27 22h 47m 45s -39° 22’ 33” 38.30 Grus
2022 Jun 28 22h 47m 03s -39° 27’ 56” 38.32 Grus
2022 Jun 29 22h 46m 19s -39° 33’ 19” 38.34 Grus
2022 Jun 30 22h 45m 36s -39° 38’ 42” 38.35 Grus
2022 Jul 01 22h 44m 50s -39° 44’ 03” 38.37 Grus
2022 Jul 02 22h 44m 04s -39° 49’ 26” 38.39 Grus