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🌎  Greenwich, United Kingdom [change]

Comet C/2021 O1 (Nishimura)

Comet C/2021 O1 (Nishimura) is currently in the constellation of Libra. The current Right Ascension of Comet C/2021 O1 (Nishimura) is 15h 06m 59s and the Declination is -16° 36’ 08” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2021 O1 (Nishimura) is 16.40 (JPL).

Summary of key facts about Comet C/2021 O1 (Nishimura) [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]:

15h 06m 59s
-16° 36’ 08”

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 O1 (Nishimura) available on TheSkyLive:

Available Resources

Comet C/2021 O1 (Nishimura) Position and Finder Charts

Below we provide Comet C/2021 O1 (Nishimura) 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 O1 (Nishimura) in Libra on December, 01 2021
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2021 O1 (Nishimura) in Libra on December, 01 2021
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 O1 (Nishimura) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2021 O1 (Nishimura)
RA: 15h 06m 59s
Dec: -16° 36’ 08”
Deep sky finder chart for Comet C/2021 O1 (Nishimura)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2021 O1 (Nishimura)?, a page that provides all the information needed to find Comet C/2021 O1 (Nishimura) in the sky and additional links to sky charts.

Comet C/2021 O1 (Nishimura) Distance from Earth

The distance of Comet C/2021 O1 (Nishimura) from Earth is currently 437,164,839 kilometers, equivalent to 2.922266 Astronomical Units. Light takes 24 minutes and 18.2249 seconds to travel from Comet C/2021 O1 (Nishimura) and arrive to us.

24 minutes and 18.2249 seconds

The following chart shows the distance of Comet C/2021 O1 (Nishimura) 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 O1 (Nishimura) from Earth between January 2014 and January 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 O1 (Nishimura) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet C/2021 O1 (Nishimura) to Earth

Between January 2014 and January 2100, the closest approach of Comet C/2021 O1 (Nishimura) to Earth happens on Fri Aug 6 2021 at a distance of 1.696715 Astronomical Units, or 253,825,018 kilometers:

Fri Aug 6 2021

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

Comet C/2021 O1 (Nishimura) brightness

The current visual magnitude of Comet C/2021 O1 (Nishimura) is 16.40.


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 O1 (Nishimura), 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 O1 (Nishimura) between January 2014 and January 2100

Comet C/2021 O1 (Nishimura) rise and set times

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

Today's Comet C/2021 O1 (Nishimura) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 106.5°
Max altitude: 22.0°
Azimuth: 253.4°

The rise and set times are defined as the time at which the upper limb of Comet C/2021 O1 (Nishimura) 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 O1 (Nishimura) Orbital Elements

The following table lists the orbital elements of Comet C/2021 O1 (Nishimura) at epoch 26 July 2021 00:00 UTC (JD: 2459422.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 1.00308870
Orbit inclination i 27.56772660°
Perihelion distance q 0.78741771 AU
117,796,013 km
Aphelion distance Q n.a.
Semi-major axis a n.a.
Orbital period period n.a.
Date of perihelion transit Tp 2021-Aug-13 22:14:39
2,459,440.4269 JD
Argument of perihelion peri 74.436267300269°
Longitude of the ascending node node 41.631473012222°
Mean anomaly M -0.0043407431881804°
Mean motion n 0.00024214°/day

Visualization of Comet C/2021 O1 (Nishimura) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2021 O1 (Nishimura) with respect of the Sun and the orbits of the major planets. The position of Comet C/2021 O1 (Nishimura) 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 O1 (Nishimura)
View Comet C/2021 O1 (Nishimura) in the 3D Solar System Simulator

Comet C/2021 O1 (Nishimura) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2021 O1 (Nishimura) 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 O1 (Nishimura) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2021 Nov 24 14h 53m 20s -14° 52’ 23” 16.12 Libra
2021 Nov 25 14h 55m 09s -15° 06’ 29” 16.16 Libra
2021 Nov 26 14h 56m 57s -15° 20’ 26” 16.19 Libra
2021 Nov 27 14h 58m 45s -15° 34’ 10” 16.23 Libra
2021 Nov 28 15h 00m 33s -15° 47’ 44” 16.27 Libra
2021 Nov 29 15h 02m 20s -16° 01’ 09” 16.30 Libra
2021 Nov 30 15h 04m 05s -16° 14’ 21” 16.34 Libra
2021 Dec 01 15h 05m 49s -16° 27’ 24” 16.38 Libra
2021 Dec 02 15h 07m 33s -16° 40’ 18” 16.41 Libra
2021 Dec 03 15h 09m 16s -16° 53’ 03” 16.45 Libra
2021 Dec 04 15h 10m 59s -17° 05’ 36” 16.48 Libra
2021 Dec 05 15h 12m 41s -17° 18’ 01” 16.51 Libra
2021 Dec 06 15h 14m 21s -17° 30’ 16” 16.55 Libra
2021 Dec 07 15h 16m 00s -17° 42’ 23” 16.58 Libra