C/2020 K3 (Leonard)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	1 Jun 2020	19.3	1.583 AU	1.824 AU	00h01m	+41°40'	60.0°	33.7°	266°
Nearest approach	11 Jul 2020	18.9	1.676 AU	1.307 AU	18h53m	+66°20'	91.4°	37.3°	173°
Today	5 Nov 2025	34.2	15.936 AU	16.725 AU	12h10m	-23°11'	36.2°	2.1°	265°

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 16.0 + 5 log[∆] + 10.0 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/2020 K3 (Leonard) are:

    e (Eccentricity)                : 1.0000000
    q (Perihelion distance)         : 1.5830690
    i (Inclination)                 : 129.01520
    Ω (Longitude of ascending node) : 28.35460
    ω (Argument of perihelion)      : 64.49240
    L (Longitude of perihelion)     : -24.48574
    B (Latitude of perihelion)      : 44.52701
    T (Time of perihelion passage)  : 2459001.50310

    Epoch                           : 
    Reference                       : MPEC 2020-KF9

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-11-04 00:00 UT   12 10 13.2   -23 08 51    16.728   15.929   35.2    2.1   264   34.2 
2025-11-05 00:00 UT   12 10 22.3   -23 10 53    16.726   15.935   36.0    2.1   265   34.2 
2025-11-05 05:53 UT   12 10 24.5   -23 11 23    16.725   15.936   36.2    2.1   265   34.2 
2025-11-06 00:00 UT   12 10 31.3   -23 12 54    16.723   15.941   36.8    2.1   266   34.2 
2025-11-07 00:00 UT   12 10 40.1   -23 14 56    16.720   15.946   37.6    2.2   267   34.2 
2025-11-08 00:00 UT   12 10 48.8   -23 16 58    16.716   15.952   38.4    2.2   267   34.2 
2025-11-09 00:00 UT   12 10 57.3   -23 19 00    16.713   15.958   39.2    2.2   268   34.2 
2025-11-10 00:00 UT   12 11 05.7   -23 21 03    16.709   15.964   40.0    2.3   269   34.2 
2025-11-11 00:00 UT   12 11 13.9   -23 23 05    16.705   15.970   40.8    2.3   270   34.2 
2025-11-12 00:00 UT   12 11 21.9   -23 25 07    16.701   15.975   41.7    2.4   271   34.2 
2025-11-13 00:00 UT   12 11 29.8   -23 27 10    16.696   15.981   42.5    2.4   271   34.2 
2025-11-14 00:00 UT   12 11 37.4   -23 29 12    16.692   15.987   43.3    2.4   272   34.2 
2025-11-15 00:00 UT   12 11 44.9   -23 31 15    16.687   15.993   44.2    2.5   273   34.2 

    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.