C/2018 R3 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	24 May 2019	11.7	1.302 AU	1.917 AU	03h35m	+59°43'	39.3°	29.5°	350°
Perihelion	8 Jun 2019	11.6	1.283 AU	1.957 AU	05h45m	+57°56'	36.0°	27.7°	17°
Today	19 Nov 2024	34.9	16.214 AU	16.568 AU	10h28m	-66°49'	67.4°	3.2°	267°

The interactive orbit chart above shows the comet's path through the solar system and its position at the given date. Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below. (Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)

The orbital elements of C/2018 R3 (Lemmon) are:

            e (Eccentricity)                : 0.9992540
            q (Perihelion distance)         : 1.2826970
            i (Inclination)                 : 69.69760
            Ω (Longitude of ascending node) : 324.42830
            ω (Argument of perihelion)      : 112.75850
            L (Longitude of perihelion)     : 284.83424
            B (Latitude of perihelion)      : 59.86614
            T (Time of perihelion passage)  : 2458642.61920
            P (Orbital period in years)     : 71298.09

            Epoch                           : 2024 Nov 18
            Reference                       : MPC118841

            Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)
        

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (9.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 8.34 + 5 log[∆] + 16.91 log[r]).

The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.

The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2024-11-19 00:00 UT   10 28 22.8   -66 46 08    16.566   16.209   67.2    3.2   266   34.9 
2024-11-19 20:41 UT   10 28 26.5   -66 49 28    16.568   16.214   67.4    3.2   267   34.9 
2024-11-20 00:00 UT   10 28 27.0   -66 50 00    16.568   16.215   67.4    3.2   267   34.9 
2024-11-21 00:00 UT   10 28 30.7   -66 53 53    16.570   16.221   67.6    3.2   268   34.9 
2024-11-22 00:00 UT   10 28 33.9   -66 57 45    16.573   16.227   67.8    3.2   270   34.9 
2024-11-23 00:00 UT   10 28 36.4   -67 01 37    16.575   16.232   68.1    3.2   271   34.9 
2024-11-24 00:00 UT   10 28 38.3   -67 05 30    16.577   16.238   68.3    3.2   272   34.9 
2024-11-25 00:00 UT   10 28 39.7   -67 09 22    16.579   16.244   68.5    3.2   273   34.9 
2024-11-26 00:00 UT   10 28 40.5   -67 13 14    16.581   16.250   68.7    3.2   274   34.9 
2024-11-27 00:00 UT   10 28 40.6   -67 17 06    16.583   16.256   69.0    3.2   275   34.9 
2024-11-28 00:00 UT   10 28 40.2   -67 20 57    16.585   16.261   69.2    3.3   276   34.9 
2024-11-29 00:00 UT   10 28 39.1   -67 24 48    16.586   16.267   69.5    3.3   277   34.9 

    Terminology:
            
    delta:  distance between comet and earth in AU
    radius: distance between comet and sun in AU
    magn:   magnitude (brightness) estimate    
    ra:     right ascension in hours (24h = 360deg)
    dec:    declination in degrees
    elong:  elongation in degrees (angle sun-earth-comet)    
    phase:  phase angle in degrees (angle sun-comet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km      
    

Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or the MPC (Minor Planet Center)
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.