C/2020 X4 (Leonard)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Nov 2020	19.7	5.225 AU	5.173 AU	20h39m	+22°47'	87.5°	10.9°	69°
Nearest approach	27 Aug 2021	19.8	5.589 AU	4.602 AU	22h37m	+02°55'	166.5°	2.4°	195°
Today	31 Jan 2025	24.7	10.992 AU	11.413 AU	01h24m	-50°51'	62.4°	4.6°	96°

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 X4 (Leonard) are:

            e (Eccentricity)                : 0.8714150
            q (Perihelion distance)         : 5.2248850
            i (Inclination)                 : 80.65000
            Ω (Longitude of ascending node) : 161.94090
            ω (Argument of perihelion)      : 140.30860
            L (Longitude of perihelion)     : 154.26147
            B (Latitude of perihelion)      : 39.06247
            T (Time of perihelion passage)  : 2459169.08550
            P (Orbital period in years)     : 259.02

            Epoch                           : 2025 Jan 30
            Reference                       : MPEC 2021-S45

            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 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. (9.00 + 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
2025-01-31 00:00 UT   01 24 37.4   -50 52 22    11.411   10.991   62.5    4.6    96   24.7 
2025-01-31 06:14 UT   01 24 41.9   -50 51 25    11.413   10.992   62.4    4.6    96   24.7 
2025-02-01 00:00 UT   01 24 54.9   -50 48 42    11.422   10.996   62.1    4.5    97   24.7 
2025-02-02 00:00 UT   01 25 12.9   -50 45 02    11.433   11.001   61.8    4.5    98   24.7 
2025-02-03 00:00 UT   01 25 31.4   -50 41 23    11.443   11.005   61.4    4.5    99   24.7 
2025-02-04 00:00 UT   01 25 50.2   -50 37 45    11.454   11.010   61.0    4.5   100   24.7 
2025-02-05 00:00 UT   01 26 09.4   -50 34 08    11.464   11.015   60.6    4.5   101   24.7 
2025-02-06 00:00 UT   01 26 29.1   -50 30 33    11.475   11.020   60.3    4.5   102   24.7 
2025-02-07 00:00 UT   01 26 49.1   -50 26 58    11.485   11.025   59.9    4.4   103   24.7 
2025-02-08 00:00 UT   01 27 09.6   -50 23 25    11.495   11.029   59.6    4.4   104   24.7 
2025-02-09 00:00 UT   01 27 30.4   -50 19 53    11.505   11.034   59.3    4.4   105   24.7 
2025-02-10 00:00 UT   01 27 51.6   -50 16 22    11.515   11.039   58.9    4.4   106   24.7 

    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.