22P/Kopff
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	25 Dec 2025	23.4	5.172 AU	4.273 AU	08h08m	+19°39'	153.6°	4.8°	283°
Perihelion	29 Jun 2028	8.9	1.452 AU	0.452 AU	19h48m	-16°28'	161.3°	13.0°	246°
Nearest approach	9 Jul 2028	8.9	1.457 AU	0.445 AU	19h55m	-18°04'	169.8°	7.1°	244°

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 7.8 + 5 log[∆] + 17.4 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 22P/Kopff are:

    e (Eccentricity)                : 0.5710000
    q (Perihelion distance)         : 1.4523970
    i (Inclination)                 : 4.96590
    Ω (Longitude of ascending node) : 119.93590
    ω (Argument of perihelion)      : 163.41520
    L (Longitude of perihelion)     : 103.40995
    B (Latitude of perihelion)      : 1.41581
    T (Time of perihelion passage)  : 2461951.98420
    P (Orbital period in years)     : 6.23

    Epoch                           : 2025 Dec 24
    Reference                       : MPEC 2025-W75

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.856

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-24 00:00 UT   08 09 24.1   +19 35 60     4.287    5.174  151.8    5.2   283   23.4 
2025-12-25 00:00 UT   08 08 49.6   +19 38 03     4.278    5.173  152.9    5.0   283   23.4 
2025-12-25 14:21 UT   08 08 28.7   +19 39 18     4.273    5.172  153.6    4.8   283   23.4 
2025-12-26 00:00 UT   08 08 14.6   +19 40 09     4.269    5.172  154.1    4.8   283   23.4 
2025-12-27 00:00 UT   08 07 38.9   +19 42 16     4.261    5.170  155.3    4.6   283   23.4 
2025-12-28 00:00 UT   08 07 02.7   +19 44 24     4.253    5.169  156.4    4.4   283   23.3 
2025-12-29 00:00 UT   08 06 25.9   +19 46 34     4.245    5.168  157.6    4.2   283   23.3 
2025-12-30 00:00 UT   08 05 48.6   +19 48 45     4.237    5.166  158.8    4.0   283   23.3 
2025-12-31 00:00 UT   08 05 10.8   +19 50 57     4.230    5.165  159.9    3.7   283   23.3 
2026-01-01 00:00 UT   08 04 32.4   +19 53 10     4.223    5.164  161.1    3.5   283   23.3 
2026-01-02 00:00 UT   08 03 53.7   +19 55 24     4.217    5.162  162.3    3.3   283   23.3 
2026-01-03 00:00 UT   08 03 14.4   +19 57 39     4.211    5.161  163.5    3.1   283   23.3 
2026-01-04 00:00 UT   08 02 34.8   +19 59 55     4.205    5.159  164.6    2.9   283   23.3 

    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.