C/2022 W3 (Leonard)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	22 Jun 2023	16.2	1.395 AU	1.557 AU	01h14m	+65°11'	61.5°	39.8°	276°
Nearest approach	15 Aug 2023	15.2	1.591 AU	0.755 AU	19h50m	+31°33'	127.7°	30.3°	147°
Today	30 Apr 2026	28.8	10.052 AU	9.889 AU	02h43m	-81°44'	96.5°	5.7°	176°

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 13.8 + 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/2022 W3 (Leonard) are:

    e (Eccentricity)                : 0.9949590
    q (Perihelion distance)         : 1.3952850
    i (Inclination)                 : 103.58990
    Ω (Longitude of ascending node) : 132.32630
    ω (Argument of perihelion)      : 116.48800
    L (Longitude of perihelion)     : 157.57138
    B (Latitude of perihelion)      : 60.45506
    T (Time of perihelion passage)  : 2460118.44940
    P (Orbital period in years)     : 4604.89

    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
2026-04-29 00:00 UT   02 39 39.6   -81 44 46     9.887   10.043   96.0    5.7   176   28.8 
2026-04-30 00:00 UT   02 42 44.7   -81 44 49     9.888   10.050   96.4    5.7   176   28.8 
2026-04-30 07:57 UT   02 43 46.1   -81 44 50     9.889   10.052   96.5    5.7   176   28.8 
2026-05-01 00:00 UT   02 45 50.0   -81 44 52     9.890   10.057   96.7    5.7   177   28.8 
2026-05-02 00:00 UT   02 48 55.5   -81 44 56     9.892   10.064   97.0    5.7   177   28.8 
2026-05-03 00:00 UT   02 52 01.1   -81 45 01     9.894   10.071   97.3    5.7   177   28.8 
2026-05-04 00:00 UT   02 55 06.8   -81 45 07     9.896   10.078   97.6    5.7   177   28.8 
2026-05-05 00:00 UT   02 58 12.7   -81 45 13     9.898   10.085   97.8    5.7   177   28.8 
2026-05-06 00:00 UT   03 01 18.7   -81 45 19     9.900   10.092   98.1    5.7   177   28.8 
2026-05-07 00:00 UT   03 04 24.9   -81 45 27     9.902   10.099   98.4    5.7   178   28.8 
2026-05-08 00:00 UT   03 07 31.2   -81 45 35     9.904   10.106   98.7    5.7   178   28.8 
2026-05-09 00:00 UT   03 10 37.7   -81 45 43     9.906   10.113   99.0    5.7   178   28.8 
2026-05-10 00:00 UT   03 13 44.3   -81 45 52     9.909   10.120   99.2    5.7   178   28.8 

    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.