C/2017 K1 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	11 Mar 2018	19.7	7.263 AU	6.682 AU	15h06m	-15°30'	122.3°	6.6°	285°
Nearest approach	29 Apr 2018	19.6	7.269 AU	6.264 AU	14h31m	-10°51'	176.2°	0.5°	201°
Today	19 Oct 2026	26.2	18.980 AU	19.009 AU	08h34m	+44°11'	86.8°	3.0°	287°

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. (7.0 + 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/2017 K1 (PANSTARRS) are:

    e (Eccentricity)                : 0.9996020
    q (Perihelion distance)         : 7.2626290
    i (Inclination)                 : 154.03090
    Ω (Longitude of ascending node) : 225.66440
    ω (Argument of perihelion)      : 4.07370
    L (Longitude of perihelion)     : 222.00084
    B (Latitude of perihelion)      : 1.78260
    T (Time of perihelion passage)  : 2458189.39170

    Epoch                           : 2026 Oct 19
    Reference                       : MPC194151

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-10-18 00:00 UT   08 34 21.9   +44 09 17    19.029   18.973   85.3    3.0   288   26.2 
2026-10-19 00:00 UT   08 34 21.3   +44 10 35    19.017   18.977   86.2    3.0   288   26.2 
2026-10-19 17:32 UT   08 34 20.7   +44 11 33    19.009   18.980   86.8    3.0   287   26.2 
2026-10-20 00:00 UT   08 34 20.4   +44 11 54    19.006   18.981   87.1    3.0   287   26.2 
2026-10-21 00:00 UT   08 34 19.3   +44 13 14    18.994   18.986   88.0    3.0   287   26.2 
2026-10-22 00:00 UT   08 34 17.8   +44 14 35    18.983   18.990   88.9    3.0   286   26.2 
2026-10-23 00:00 UT   08 34 16.1   +44 15 57    18.971   18.994   89.8    3.0   286   26.2 
2026-10-24 00:00 UT   08 34 14.0   +44 17 20    18.960   18.999   90.7    3.0   285   26.2 
2026-10-25 00:00 UT   08 34 11.7   +44 18 44    18.948   19.003   91.7    3.0   285   26.2 
2026-10-26 00:00 UT   08 34 09.1   +44 20 09    18.937   19.008   92.6    3.0   285   26.2 
2026-10-27 00:00 UT   08 34 06.2   +44 21 35    18.925   19.012   93.5    3.0   284   26.2 
2026-10-28 00:00 UT   08 34 02.9   +44 23 02    18.914   19.016   94.4    3.0   284   26.2 
2026-10-29 00:00 UT   08 33 59.4   +44 24 29    18.902   19.021   95.3    3.0   283   26.2 

    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.