C/2019 U6 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	18 Jun 2020	6.5	0.906 AU	0.860 AU	08h52m	-11°33'	57.0°	70.2°	128°
Nearest approach	28 Jun 2020	6.5	0.926 AU	0.817 AU	10h10m	-03°16'	59.4°	71.1°	119°
Today	17 Sep 2025	32.6	16.024 AU	15.426 AU	23h22m	+52°35'	125.0°	2.9°	175°

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)                : 0.9970010
            q (Perihelion distance)         : 0.9056850
            i (Inclination)                 : 60.99350
            Ω (Longitude of ascending node) : 235.73710
            ω (Argument of perihelion)      : 329.42180
            L (Longitude of perihelion)     : 219.74875
            B (Latitude of perihelion)      : -26.41715
            T (Time of perihelion passage)  : 2459018.84880
            P (Orbital period in years)     : 5248.09

            Epoch                           : 2025 Sep 16
            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[∆] + 15.88 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
2025-09-17 00:00 UT   23 22 33.6   +52 35 40    15.426   16.023  124.9    2.9   175   32.6 
2025-09-17 05:47 UT   23 22 28.6   +52 35 22    15.426   16.024  125.0    2.9   175   32.6 
2025-09-18 00:00 UT   23 22 12.8   +52 34 25    15.427   16.029  125.3    2.9   174   32.6 
2025-09-19 00:00 UT   23 21 52.0   +52 33 07    15.428   16.035  125.6    2.9   173   32.6 
2025-09-20 00:00 UT   23 21 31.3   +52 31 46    15.430   16.041  125.9    2.9   172   32.6 
2025-09-21 00:00 UT   23 21 10.6   +52 30 21    15.431   16.046  126.3    2.9   170   32.6 
2025-09-22 00:00 UT   23 20 50.1   +52 28 53    15.433   16.052  126.6    2.9   169   32.6 
2025-09-23 00:00 UT   23 20 29.6   +52 27 22    15.435   16.058  126.9    2.9   168   32.6 
2025-09-24 00:00 UT   23 20 09.2   +52 25 47    15.438   16.064  127.1    2.9   166   32.6 
2025-09-25 00:00 UT   23 19 49.0   +52 24 09    15.440   16.070  127.4    2.8   165   32.6 
2025-09-26 00:00 UT   23 19 28.8   +52 22 28    15.443   16.075  127.7    2.8   164   32.6 
2025-09-27 00:00 UT   23 19 08.8   +52 20 44    15.446   16.081  127.9    2.8   163   32.6 

    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.