C/2019 U6 (Lemmon)
ephemeris date magn radius delta ra dec elong phase PA
Perihelion18 Jun 20206.50.906 AU0.860 AU08h52m-11°35'57.1°70.2°128°
Nearest approach28 Jun 20206.50.926 AU0.817 AU10h10m-03°18'59.5°71.0°120°
Today5 Jul 202532.515.595 AU15.675 AU23h41m+51°37'83.6°3.7°241°
C/2019 U6 (Lemmon)- 2025-07-05
astro.vanbuitenen.nl


 
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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/2019 U6 (Lemmon) are:

            e (Eccentricity)                : 0.9970150
            q (Perihelion distance)         : 0.9064950
            i (Inclination)                 : 60.98650
            Ω (Longitude of ascending node) : 235.74980
            ω (Argument of perihelion)      : 329.43010
            L (Longitude of perihelion)     : 219.76313
            B (Latitude of perihelion)      : -26.40824
            T (Time of perihelion passage)  : 2459018.81910
            P (Orbital period in years)     : 5292.14

            Epoch                           : 2025 Jul 05
            Reference                       : MPEC 2022-H04

            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 (10.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 7.50 + 5 log[∆] + 15.90 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
2025-07-05 00:00 UT   23 41 52.6   +51 34 54    15.680   15.590   83.0    3.7   242   32.4 
2025-07-05 23:32 UT   23 41 47.4   +51 37 18    15.675   15.595   83.6    3.7   241   32.5 
2025-07-06 00:00 UT   23 41 47.3   +51 37 21    15.675   15.595   83.6    3.7   241   32.5 
2025-07-07 00:00 UT   23 41 41.6   +51 39 46    15.669   15.601   84.3    3.7   240   32.5 
2025-07-08 00:00 UT   23 41 35.5   +51 42 10    15.664   15.607   84.9    3.7   240   32.5 
2025-07-09 00:00 UT   23 41 29.1   +51 44 31    15.659   15.613   85.5    3.7   239   32.5 
2025-07-10 00:00 UT   23 41 22.3   +51 46 51    15.653   15.619   86.2    3.7   238   32.5 
2025-07-11 00:00 UT   23 41 15.2   +51 49 09    15.648   15.625   86.8    3.7   237   32.5 
2025-07-12 00:00 UT   23 41 07.7   +51 51 25    15.643   15.631   87.4    3.7   237   32.5 
2025-07-13 00:00 UT   23 40 59.9   +51 53 39    15.637   15.637   88.1    3.7   236   32.5 
2025-07-14 00:00 UT   23 40 51.7   +51 55 51    15.632   15.643   88.7    3.7   235   32.5 
2025-07-15 00:00 UT   23 40 43.1   +51 58 01    15.626   15.648   89.3    3.7   234   32.5 

































































    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.