C/2017 K2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	13 Jul 2022	8.9	2.640 AU	1.787 AU	16h59m	-03°52'	139.1°	14.6°	119°
Perihelion	17 Dec 2022	8.4	1.801 AU	2.485 AU	17h50m	-60°22'	37.1°	19.2°	176°
Today	28 Oct 2026	17.6	12.275 AU	11.726 AU	06h12m	+35°09'	121.5°	4.0°	264°

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 4.7 + 5 log[∆] + 7.0 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/2017 K2 (PANSTARRS) are:

    e (Eccentricity)                : 0.9982720
    q (Perihelion distance)         : 1.8006940
    i (Inclination)                 : 87.65490
    Ω (Longitude of ascending node) : 88.22430
    ω (Argument of perihelion)      : 236.14090
    L (Longitude of perihelion)     : 91.71427
    B (Latitude of perihelion)      : -56.06945
    T (Time of perihelion passage)  : 2459931.12090
    P (Orbital period in years)     : 33639.09

    Epoch                           : 2026 Oct 23
    Reference                       : MPEC 2026-TP0

    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
2026-10-27 00:00 UT   06 13 16.8   +35 06 06    11.740   12.264  119.7    4.0   265   17.6 
2026-10-28 00:00 UT   06 13 03.5   +35 07 48    11.732   12.270  120.8    4.0   264   17.6 
2026-10-28 18:48 UT   06 12 52.8   +35 09 08    11.726   12.275  121.5    4.0   264   17.6 
2026-10-29 00:00 UT   06 12 49.8   +35 09 30    11.724   12.277  121.8    3.9   264   17.6 
2026-10-30 00:00 UT   06 12 35.7   +35 11 11    11.717   12.283  122.8    3.9   264   17.6 
2026-10-31 00:00 UT   06 12 21.2   +35 12 52    11.709   12.290  123.8    3.9   263   17.6 
2026-11-01 00:00 UT   06 12 06.4   +35 14 32    11.702   12.296  124.8    3.8   263   17.6 
2026-11-02 00:00 UT   06 11 51.1   +35 16 12    11.695   12.302  125.8    3.8   262   17.6 
2026-11-03 00:00 UT   06 11 35.5   +35 17 51    11.688   12.309  126.8    3.7   262   17.6 
2026-11-04 00:00 UT   06 11 19.5   +35 19 29    11.681   12.315  127.9    3.6   262   17.6 
2026-11-05 00:00 UT   06 11 03.1   +35 21 07    11.674   12.321  128.9    3.6   261   17.6 
2026-11-06 00:00 UT   06 10 46.4   +35 22 44    11.668   12.328  129.9    3.5   261   17.6 
2026-11-07 00:00 UT   06 10 29.3   +35 24 21    11.662   12.334  130.9    3.5   260   17.6 

    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.