C/2020 W5 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	30 Nov 2020	22.3	3.371 AU	2.518 AU	04h55m	+56°43'	144.7°	9.7°	191°
Nearest approach	1 Dec 2020	22.3	3.371 AU	2.518 AU	04h53m	+56°58'	144.7°	9.7°	188°
Today	19 Jul 2025	31.7	13.089 AU	12.507 AU	16h56m	+16°06'	123.1°	3.7°	129°

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/2020 W5 (Lemmon) are:

            e (Eccentricity)                : 1.0021780
            q (Perihelion distance)         : 3.3709980
            i (Inclination)                 : 88.61520
            Ω (Longitude of ascending node) : 75.46740
            ω (Argument of perihelion)      : 24.60860
            L (Longitude of perihelion)     : 76.10157
            B (Latitude of perihelion)      : 24.60094
            T (Time of perihelion passage)  : 2459184.44540

            Epoch                           : 2025 Jul 17
            Reference                       : MPEC 2021-BE3

            Classification(s):              : Nearly isotropic; New (a > 10000 AU)
        

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 light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (15.00 + 5 log[∆] + 10.00 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
2025-07-19 00:00 UT   16 56 47.5   +16 06 16    12.506   13.089  123.1    3.7   129   31.7 
2025-07-19 01:24 UT   16 56 46.7   +16 06 07    12.507   13.089  123.1    3.7   129   31.7 
2025-07-20 00:00 UT   16 56 33.2   +16 03 38    12.521   13.095  122.4    3.8   128   31.7 
2025-07-21 00:00 UT   16 56 19.1   +16 00 58    12.537   13.101  121.8    3.8   127   31.7 
2025-07-22 00:00 UT   16 56 05.3   +15 58 16    12.552   13.106  121.1    3.8   126   31.7 
2025-07-23 00:00 UT   16 55 51.7   +15 55 31    12.568   13.112  120.4    3.8   126   31.7 
2025-07-24 00:00 UT   16 55 38.5   +15 52 45    12.584   13.118  119.7    3.9   125   31.7 
2025-07-25 00:00 UT   16 55 25.4   +15 49 57    12.600   13.124  119.0    3.9   124   31.7 
2025-07-26 00:00 UT   16 55 12.7   +15 47 07    12.616   13.130  118.4    3.9   123   31.7 
2025-07-27 00:00 UT   16 55 00.3   +15 44 14    12.633   13.135  117.7    3.9   122   31.7 
2025-07-28 00:00 UT   16 54 48.1   +15 41 21    12.649   13.141  116.9    3.9   122   31.7 
2025-07-29 00:00 UT   16 54 36.2   +15 38 25    12.666   13.147  116.2    4.0   121   31.7 

    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.