C/2017 K2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	13 Jul 2022	8.9	2.644 AU	1.791 AU	16h59m	-03°44'	139.0°	14.6°	119°
Perihelion	18 Dec 2022	8.5	1.800 AU	2.485 AU	17h52m	-60°22'	37.1°	19.2°	176°
Today	5 Feb 2026	16.8	10.529 AU	9.905 AU	05h33m	+31°09'	127.1°	4.3°	93°

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 4.8 + 5 log[∆] + 6.9 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)                : 0.9985400
    q (Perihelion distance)         : 1.8002320
    i (Inclination)                 : 87.63900
    Ω (Longitude of ascending node) : 88.22160
    ω (Argument of perihelion)      : 236.15230
    L (Longitude of perihelion)     : 91.73666
    B (Latitude of perihelion)      : -56.07984
    T (Time of perihelion passage)  : 2459931.56330
    P (Orbital period in years)     : 43297.56

    Epoch                           : 2026 Feb 05
    Reference                       : MPEC 2026-A90

    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
2026-02-04 00:00 UT   05 33 48.5   +31 09 17     9.866   10.516  129.1    4.2    94   16.8 
2026-02-05 00:00 UT   05 33 31.3   +31 09 32     9.886   10.523  128.0    4.2    94   16.8 
2026-02-05 21:42 UT   05 33 16.2   +31 09 45     9.905   10.529  127.1    4.3    93   16.8 
2026-02-06 00:00 UT   05 33 14.6   +31 09 47     9.907   10.530  127.0    4.3    93   16.8 
2026-02-07 00:00 UT   05 32 58.4   +31 10 01     9.927   10.537  125.9    4.3    93   16.8 
2026-02-08 00:00 UT   05 32 42.6   +31 10 14     9.948   10.543  124.9    4.4    93   16.8 
2026-02-09 00:00 UT   05 32 27.3   +31 10 28     9.969   10.550  123.8    4.5    93   16.8 
2026-02-10 00:00 UT   05 32 12.4   +31 10 40     9.990   10.557  122.8    4.5    92   16.8 
2026-02-11 00:00 UT   05 31 58.0   +31 10 53    10.011   10.564  121.7    4.6    92   16.8 
2026-02-12 00:00 UT   05 31 44.1   +31 11 05    10.033   10.571  120.7    4.6    92   16.8 
2026-02-13 00:00 UT   05 31 30.7   +31 11 17    10.054   10.577  119.6    4.7    92   16.9 
2026-02-14 00:00 UT   05 31 17.7   +31 11 28    10.076   10.584  118.6    4.7    91   16.9 
2026-02-15 00:00 UT   05 31 05.2   +31 11 39    10.098   10.591  117.5    4.7    91   16.9 

    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.