Your guide to the Solar System and the night sky
🌎 Location: Greenwich, United Kingdom [change]

Comet C/2018 R3 (Lemmon)

Comet C/2018 R3 (Lemmon) is currently in the constellation of Vela. The current Right Ascension of Comet C/2018 R3 (Lemmon) is 10h 09m 18s and the Declination is -55° 28’ 59” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2018 R3 (Lemmon) is 24.70 (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]:

10h 09m 18s
-55° 28’ 59”

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/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 Vela on January, 28 2021
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2018 R3 (Lemmon) in Vela on January, 28 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/2018 R3 (Lemmon) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2018 R3 (Lemmon)
RA: 10h 09m 18s
Dec: -55° 28’ 59”
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 967,831,433 kilometers, equivalent to 6.469554 Astronomical Units. Light takes 53 minutes and 48.3382 seconds to travel from Comet C/2018 R3 (Lemmon) and arrive to us.

53 minutes and 48.3382 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 1.921762 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 24.70.


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

Comet C/2018 R3 (Lemmon) 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/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
2021 Jan 21 10h 15m 56s -54° 58’ 13” 24.66 Vela
2021 Jan 22 10h 15m 03s -55° 02’ 58” 24.66 Vela
2021 Jan 23 10h 14m 09s -55° 07’ 35” 24.67 Vela
2021 Jan 24 10h 13m 15s -55° 12’ 00” 24.68 Vela
2021 Jan 25 10h 12m 20s -55° 16’ 15” 24.68 Vela
2021 Jan 26 10h 11m 26s -55° 20’ 21” 24.69 Vela
2021 Jan 27 10h 10m 30s -55° 24’ 16” 24.70 Vela
2021 Jan 28 10h 09m 33s -55° 28’ 01” 24.70 Vela
2021 Jan 29 10h 08m 35s -55° 31’ 36” 24.71 Vela
2021 Jan 30 10h 07m 37s -55° 34’ 59” 24.71 Vela
2021 Jan 31 10h 06m 39s -55° 38’ 12” 24.72 Vela
2021 Feb 01 10h 05m 40s -55° 41’ 16” 24.73 Vela
2021 Feb 02 10h 04m 41s -55° 44’ 08” 24.73 Vela
2021 Feb 03 10h 03m 42s -55° 46’ 49” 24.74 Vela