C/2017 F2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	27 Nov 2017	20.2	6.900 AU	7.345 AU	13h19m	+20°41'	59.7°	7.1°	312°
Nearest approach	31 Mar 2018	19.8	6.947 AU	6.042 AU	13h23m	+20°29'	153.0°	3.7°	206°
Today	8 Nov 2026	27.0	19.652 AU	20.212 AU	18h02m	-58°54'	54.4°	2.4°	120°

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. (7.5 + 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/2017 F2 (PANSTARRS) are:

    e (Eccentricity)                : 1.0024320
    q (Perihelion distance)         : 6.8997120
    i (Inclination)                 : 42.52370
    Ω (Longitude of ascending node) : 38.62150
    ω (Argument of perihelion)      : 134.79430
    L (Longitude of perihelion)     : 2.03468
    B (Latitude of perihelion)      : 28.66207
    T (Time of perihelion passage)  : 2458085.10410

    Epoch                           : 2026 Nov 07
    Reference                       : MPC194151

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-11-07 00:00 UT   18 01 27.3   -58 56 37    20.188   19.645   55.6    2.4   119   27.0 
2026-11-08 00:00 UT   18 01 47.6   -58 55 39    20.202   19.649   54.9    2.4   120   27.0 
2026-11-08 16:53 UT   18 02 02.1   -58 54 59    20.212   19.652   54.4    2.4   120   27.0 
2026-11-09 00:00 UT   18 02 08.2   -58 54 42    20.216   19.654   54.2    2.3   121   27.0 
2026-11-10 00:00 UT   18 02 29.1   -58 53 46    20.230   19.658   53.6    2.3   121   27.0 
2026-11-11 00:00 UT   18 02 50.1   -58 52 51    20.244   19.663   52.9    2.3   122   27.0 
2026-11-12 00:00 UT   18 03 11.4   -58 51 58    20.257   19.667   52.2    2.3   123   27.0 
2026-11-13 00:00 UT   18 03 32.9   -58 51 05    20.271   19.671   51.6    2.3   124   27.0 
2026-11-14 00:00 UT   18 03 54.6   -58 50 14    20.284   19.676   50.9    2.2   125   27.0 
2026-11-15 00:00 UT   18 04 16.5   -58 49 24    20.297   19.680   50.3    2.2   126   27.0 
2026-11-16 00:00 UT   18 04 38.6   -58 48 35    20.310   19.685   49.7    2.2   126   27.0 
2026-11-17 00:00 UT   18 05 00.9   -58 47 48    20.323   19.689   49.1    2.2   127   27.0 
2026-11-18 00:00 UT   18 05 23.3   -58 47 01    20.335   19.694   48.4    2.2   128   27.0 

    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.