C/2023 V5 (Leonard)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	3 Nov 2023	18.8	1.122 AU	0.225 AU	23h08m	-17°19'	120.1°	49.9°	60°
Perihelion	13 Dec 2023	20.5	0.846 AU	0.892 AU	18h40m	+26°44'	53.3°	68.9°	22°
Today	27 Sep 2026	37.0	10.482 AU	11.269 AU	13h40m	-32°35'	36.6°	3.3°	143°

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. 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. (21.5 + 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/2023 V5 (Leonard) are:

    e (Eccentricity)                : 1.0080270
    q (Perihelion distance)         : 0.8463660
    i (Inclination)                 : 73.46460
    Ω (Longitude of ascending node) : 31.50060
    ω (Argument of perihelion)      : 57.02670
    L (Longitude of perihelion)     : 55.18789
    B (Latitude of perihelion)      : 53.53594
    T (Time of perihelion passage)  : 2460292.45420

    Epoch                           : 2026 May 29
    Reference                       : MPC194186

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-09-26 00:00 UT   13 39 49.6   -32 32 34    11.238   10.467   38.0    3.4   141   37.0 
2026-09-27 00:00 UT   13 40 11.0   -32 34 10    11.254   10.474   37.3    3.3   142   37.0 
2026-09-27 23:35 UT   13 40 32.2   -32 35 46    11.269   10.482   36.6    3.3   143   37.0 
2026-09-28 00:00 UT   13 40 32.6   -32 35 47    11.269   10.482   36.6    3.3   143   37.0 
2026-09-29 00:00 UT   13 40 54.3   -32 37 27    11.284   10.489   35.9    3.2   144   37.0 
2026-09-30 00:00 UT   13 41 16.0   -32 39 09    11.299   10.497   35.1    3.1   145   37.0 
2026-10-01 00:00 UT   13 41 37.9   -32 40 53    11.314   10.504   34.4    3.1   146   37.0 
2026-10-02 00:00 UT   13 41 59.8   -32 42 39    11.329   10.511   33.7    3.0   147   37.0 
2026-10-03 00:00 UT   13 42 21.9   -32 44 26    11.343   10.519   33.0    3.0   148   37.0 
2026-10-04 00:00 UT   13 42 44.0   -32 46 16    11.357   10.526   32.4    2.9   149   37.0 
2026-10-05 00:00 UT   13 43 06.2   -32 48 08    11.371   10.534   31.7    2.9   150   37.0 
2026-10-06 00:00 UT   13 43 28.5   -32 50 02    11.385   10.541   31.0    2.8   151   37.0 
2026-10-07 00:00 UT   13 43 50.8   -32 51 57    11.398   10.548   30.4    2.7   152   37.0 

    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.