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

Comet C/2018 R3 (Lemmon)

Available Resources

Comet C/2018 R3 (Lemmon) Position

Comet C/2018 R3 (Lemmon) is currently in the constellation of Pyxis. The current Right Ascension is 08h 51m 20s and the Declination is -34° 08’ 41”.

08h 51m 20s
-34° 08’ 41”

Simplified sky chart showing where Comet C/2018 R3 (Lemmon) is right now in the sky with respect to the brightest stars and constellations (see full screen Online Planetarium)

Map showing Comet C/2018 R3 (Lemmon) in Pyxis on April, 07 2020
Field of view: 60x30 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 showing where Comet C/2018 R3 (Lemmon) is right now (view fullscreen)

C/2018 R3 (Lemmon)
RA: 08h 51m 20s
Dec: -34° 08’ 41”
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

The distance of Comet C/2018 R3 (Lemmon) from Earth is currently 530,297,093 kilometers, equivalent to 3.544817 Astronomical Units. Light takes 29 minutes and 28.8807 seconds to travel from Comet C/2018 R3 (Lemmon) and arrive to us.

29 minutes and 28.8807 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 1.92176202 Astronomical Units, or 287,491,506 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 20.92.


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: 124.1°
Max altitude: 4.4°
Azimuth: 235.9°
Comet C/2018 R3 (Lemmon) is below the horizon from Greenwich, United Kingdom

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 0.99934503
Orbit inclination i 69.71540696°
Perihelion distance q 1.29060200 AU
193,071,312 km
Aphelion distance Q 3,939.67757561 AU
589,367,377,737 km
Semi-major axis a 1,970.48408881 AU
294,780,224,525 km
Orbital period period 87,471.7100 years
31,949,040.9108 days
Date of perihelion transit Tp 2019-Jun-07 04:45:17
2,458,641.6981 JD
Next perihelion transit 89492-Dec-07 02:36
34,407,682.6089 JD
Argument of perihelion peri 112.87545965238°
Longitude of the ascending node node 324.62602476655°
Mean anomaly M 359.9988371694°
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 Mar 31 08h 55m 03s -34° 59’ 54” 20.75 Pyxis
2020 Apr 01 08h 54m 28s -34° 52’ 54” 20.77 Pyxis
2020 Apr 02 08h 53m 53s -34° 45’ 54” 20.80 Pyxis
2020 Apr 03 08h 53m 21s -34° 38’ 53” 20.82 Pyxis
2020 Apr 04 08h 52m 50s -34° 31’ 53” 20.84 Pyxis
2020 Apr 05 08h 52m 22s -34° 24’ 52” 20.87 Pyxis
2020 Apr 06 08h 51m 54s -34° 17’ 53” 20.89 Pyxis
2020 Apr 07 08h 51m 29s -34° 10’ 55” 20.91 Pyxis
2020 Apr 08 08h 51m 03s -34° 03’ 59” 20.93 Pyxis
2020 Apr 09 08h 50m 40s -33° 57’ 03” 20.96 Pyxis
2020 Apr 10 08h 50m 20s -33° 50’ 11” 20.98 Pyxis
2020 Apr 11 08h 49m 59s -33° 43’ 19” 21.00 Pyxis
2020 Apr 12 08h 49m 41s -33° 36’ 32” 21.03 Pyxis
2020 Apr 13 08h 49m 24s -33° 29’ 47” 21.05 Pyxis