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🌎 Location: Greenwich, United Kingdom [change]

Comet C/2018 R3 (Lemmon)

Comet C/2018 R3 (Lemmon) is currently in the constellation of Antlia. The current Right Ascension of Comet C/2018 R3 (Lemmon) is 09h 47m 05s and the Declination is -32° 24’ 07” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2018 R3 (Lemmon) is 23.32 (JPL).

Summary of key facts about Comet C/2018 R3 (Lemmon) [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]:

09h 47m 05s
-32° 24’ 07”

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Additional information about Comet C/2018 R3 (Lemmon) available on TheSkyLive:

Available Resources

Comet C/2018 R3 (Lemmon) Position and Finder Charts

Below we provide Comet C/2018 R3 (Lemmon) 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/2018 R3 (Lemmon) in Antlia on August, 12 2020
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2018 R3 (Lemmon) in Antlia on August, 12 2020
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/2018 R3 (Lemmon) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2018 R3 (Lemmon)
RA: 09h 47m 05s
Dec: -32° 24’ 07”
Deep sky finder chart for Comet C/2018 R3 (Lemmon)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2018 R3 (Lemmon)?, a page that provides all the information needed to find Comet C/2018 R3 (Lemmon) in the sky and additional links to sky charts.

Comet C/2018 R3 (Lemmon) Distance from Earth

The distance of Comet C/2018 R3 (Lemmon) from Earth is currently 887,592,855 kilometers, equivalent to 5.933192 Astronomical Units. Light takes 49 minutes and 20.6911 seconds to travel from Comet C/2018 R3 (Lemmon) and arrive to us.

49 minutes and 20.6911 seconds

The following chart shows the distance of Comet C/2018 R3 (Lemmon) 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/2018 R3 (Lemmon) 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/2018 R3 (Lemmon) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet C/2018 R3 (Lemmon) to Earth

Between January 2013 and December 2100 the closest approach of Comet C/2018 R3 (Lemmon) to Earth happens on Thu May 23 2019 at a distance of 1.92176204 Astronomical Units, or 287,491,510 kilometers:

Thu May 23 2019

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

Comet C/2018 R3 (Lemmon) brightness

The current visual magnitude of Comet C/2018 R3 (Lemmon) is 23.32.


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/2018 R3 (Lemmon), 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/2018 R3 (Lemmon) between January 2013 and December 2100

Comet C/2018 R3 (Lemmon) 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/2018 R3 (Lemmon) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 122.4°
Max altitude: 6.1°
Azimuth: 237.6°

The rise and set times are defined as the time at which the upper limb of Comet C/2018 R3 (Lemmon) 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/2018 R3 (Lemmon) Orbital Elements

The following table lists the orbital elements of Comet C/2018 R3 (Lemmon) at epoch 23 February 2019 00:00 UTC (JD: 2458538.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.99934491
Orbit inclination i 69.71541012°
Perihelion distance q 1.29060208 AU
193,071,323 km
Aphelion distance Q 3,938.91064194 AU
589,252,646,093 km
Semi-major axis a 1,970.10062201 AU
294,722,858,708 km
Orbital period period 87,446.1700 years
31,939,715.1818 days
Date of perihelion transit Tp 2019-Jun-07 04:45:17
2,458,641.6981 JD
Next perihelion transit 89467-May-27 09:07
34,398,356.8799 JD
Argument of perihelion peri 112.87545886002°
Longitude of the ascending node node 324.62602581214°
Mean anomaly M 359.99883682987°
Mean motion n 0.00001127°/day

Visualization of Comet C/2018 R3 (Lemmon) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2018 R3 (Lemmon) with respect of the Sun and the orbits of the major planets. The position of Comet C/2018 R3 (Lemmon) 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/2018 R3 (Lemmon)
View Comet C/2018 R3 (Lemmon) in the 3D Solar System Simulator

Comet C/2018 R3 (Lemmon) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2018 R3 (Lemmon) computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet C/2018 R3 (Lemmon) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2020 Aug 05 09h 41m 18s -31° 43’ 14” 23.21 Antlia
2020 Aug 06 09h 42m 03s -31° 48’ 12” 23.22 Antlia
2020 Aug 07 09h 42m 47s -31° 53’ 14” 23.24 Antlia
2020 Aug 08 09h 43m 32s -31° 58’ 23” 23.25 Antlia
2020 Aug 09 09h 44m 17s -32° 03’ 36” 23.26 Antlia
2020 Aug 10 09h 45m 02s -32° 08’ 53” 23.28 Antlia
2020 Aug 11 09h 45m 46s -32° 14’ 16” 23.29 Antlia
2020 Aug 12 09h 46m 30s -32° 19’ 42” 23.30 Antlia
2020 Aug 13 09h 47m 14s -32° 25’ 15” 23.32 Antlia
2020 Aug 14 09h 47m 58s -32° 30’ 52” 23.33 Antlia
2020 Aug 15 09h 48m 42s -32° 36’ 34” 23.34 Antlia
2020 Aug 16 09h 49m 27s -32° 42’ 20” 23.36 Antlia
2020 Aug 17 09h 50m 11s -32° 48’ 12” 23.37 Antlia
2020 Aug 18 09h 50m 54s -32° 54’ 09” 23.38 Antlia