C/2019 U6 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	18 Jun 2020	6.5	0.904 AU	0.862 AU	08h52m	-11°27'	56.8°	70.2°	128°
Nearest approach	29 Jun 2020	6.5	0.924 AU	0.819 AU	10h10m	-03°10'	59.3°	71.1°	119°
Today	21 Apr 2026	33.4	17.259 AU	17.946 AU	23h41m	+47°57'	45.7°	2.4°	311°

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.)

Light curve

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations from COBS. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 7.5 + 5 log[∆] + 15.9 log[r]). An additional green curve is displayed when an increase in apparent brightness is expected due to forward scattering of sunlight, which occurs when a dust-rich comet is located between the Earth and the Sun. (See Marcus 2007)

Charts

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.

Orbital elements

The orbital elements of C/2019 U6 (Lemmon) are:

    e (Eccentricity)                : 0.9969810
    q (Perihelion distance)         : 0.9039010
    i (Inclination)                 : 61.02040
    Ω (Longitude of ascending node) : 235.68910
    ω (Argument of perihelion)      : 329.41500
    L (Longitude of perihelion)     : 219.70949
    B (Latitude of perihelion)      : -26.43027
    T (Time of perihelion passage)  : 2459018.97620
    P (Orbital period in years)     : 5180.68

    Epoch                           : 2026 Mar 16
    Reference                       : MPEC 2026-E44

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-04-20 00:00 UT   23 41 04.9   +47 54 45    17.941   17.252   45.4    2.4   313   33.4 
2026-04-21 00:00 UT   23 41 21.1   +47 56 50    17.945   17.257   45.6    2.4   312   33.4 
2026-04-21 08:43 UT   23 41 26.9   +47 57 36    17.946   17.259   45.7    2.4   311   33.4 
2026-04-22 00:00 UT   23 41 37.1   +47 58 57    17.948   17.263   45.8    2.4   310   33.4 
2026-04-23 00:00 UT   23 41 52.9   +48 01 05    17.952   17.269   46.0    2.4   309   33.4 
2026-04-24 00:00 UT   23 42 08.6   +48 03 14    17.955   17.274   46.2    2.4   308   33.4 
2026-04-25 00:00 UT   23 42 24.1   +48 05 24    17.958   17.280   46.4    2.4   307   33.4 
2026-04-26 00:00 UT   23 42 39.4   +48 07 36    17.961   17.285   46.6    2.4   305   33.4 
2026-04-27 00:00 UT   23 42 54.5   +48 09 49    17.963   17.291   46.8    2.4   304   33.4 
2026-04-28 00:00 UT   23 43 09.4   +48 12 03    17.966   17.297   47.1    2.4   303   33.4 
2026-04-29 00:00 UT   23 43 24.2   +48 14 19    17.968   17.302   47.3    2.5   302   33.4 
2026-04-30 00:00 UT   23 43 38.7   +48 16 35    17.970   17.308   47.6    2.5   301   33.4 
2026-05-01 00:00 UT   23 43 53.1   +48 18 53    17.972   17.313   47.9    2.5   300   33.4 

    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.