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	10 Jul 2025	31.6	13.037 AU	12.377 AU	16h59m	+16°28'	128.7°	3.5°	138°

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)                : 1.0021680
            q (Perihelion distance)         : 3.3709290
            i (Inclination)                 : 88.61530
            Ω (Longitude of ascending node) : 75.46730
            ω (Argument of perihelion)      : 24.60740
            L (Longitude of perihelion)     : 76.10139
            B (Latitude of perihelion)      : 24.59974
            T (Time of perihelion passage)  : 2459184.43640

            Epoch                           : 2025 Jul 09
            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
2025-07-10 00:00 UT   16 59 07.4   +16 28 15    12.377   13.037  128.7    3.5   138   31.6 
2025-07-10 01:27 UT   16 59 06.4   +16 28 07    12.377   13.037  128.7    3.5   138   31.6 
2025-07-11 00:00 UT   16 58 51.0   +16 25 58    12.390   13.043  128.1    3.5   137   31.6 
2025-07-12 00:00 UT   16 58 34.7   +16 23 39    12.404   13.048  127.5    3.5   136   31.6 
2025-07-13 00:00 UT   16 58 18.7   +16 21 17    12.418   13.054  126.9    3.6   135   31.6 
2025-07-14 00:00 UT   16 58 02.9   +16 18 53    12.432   13.060  126.3    3.6   134   31.6 
2025-07-15 00:00 UT   16 57 47.3   +16 16 26    12.447   13.066  125.7    3.6   133   31.6 
2025-07-16 00:00 UT   16 57 32.0   +16 13 57    12.461   13.072  125.0    3.7   132   31.6 
2025-07-17 00:00 UT   16 57 16.9   +16 11 26    12.476   13.077  124.4    3.7   131   31.6 
2025-07-18 00:00 UT   16 57 02.1   +16 08 52    12.491   13.083  123.8    3.7   130   31.7 
2025-07-19 00:00 UT   16 56 47.5   +16 06 16    12.506   13.089  123.1    3.7   129   31.7 
2025-07-20 00:00 UT   16 56 33.2   +16 03 38    12.521   13.095  122.4    3.8   128   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.