C/2017 F2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	25 Nov 2017	20.2	6.921 AU	7.397 AU	13h19m	+20°35'	57.8°	6.9°	313°
Nearest approach	31 Mar 2018	19.8	6.970 AU	6.065 AU	13h24m	+20°16'	153.1°	3.7°	206°
Today	6 Nov 2025	26.4	18.008 AU	18.603 AU	17h35m	-57°09'	51.9°	2.5°	125°

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)                : 1.0016210
    q (Perihelion distance)         : 6.9213670
    i (Inclination)                 : 42.56130
    Ω (Longitude of ascending node) : 38.71180
    ω (Argument of perihelion)      : 134.85940
    L (Longitude of perihelion)     : 2.20377
    B (Latitude of perihelion)      : 28.64910
    T (Time of perihelion passage)  : 2458082.87840

    Epoch                           : 2023 Jan 31
    Reference                       : MPC114598

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-11-05 00:00 UT   17 34 57.9   -57 10 24    18.582   18.001   52.9    2.5   123   26.4 
2025-11-06 00:00 UT   17 35 20.3   -57 09 41    18.596   18.006   52.2    2.5   124   26.4 
2025-11-06 13:17 UT   17 35 32.7   -57 09 17    18.603   18.008   51.9    2.5   125   26.4 
2025-11-07 00:00 UT   17 35 42.9   -57 08 59    18.609   18.010   51.6    2.5   125   26.4 
2025-11-08 00:00 UT   17 36 05.7   -57 08 18    18.623   18.015   50.9    2.4   126   26.4 
2025-11-09 00:00 UT   17 36 28.7   -57 07 38    18.637   18.019   50.2    2.4   127   26.4 
2025-11-10 00:00 UT   17 36 51.9   -57 07 00    18.650   18.024   49.6    2.4   127   26.4 
2025-11-11 00:00 UT   17 37 15.4   -57 06 24    18.663   18.028   48.9    2.4   128   26.4 
2025-11-12 00:00 UT   17 37 39.0   -57 05 48    18.676   18.033   48.3    2.3   129   26.4 
2025-11-13 00:00 UT   17 38 02.8   -57 05 14    18.689   18.037   47.7    2.3   130   26.4 
2025-11-14 00:00 UT   17 38 26.8   -57 04 41    18.701   18.042   47.0    2.3   131   26.4 
2025-11-15 00:00 UT   17 38 51.0   -57 04 10    18.714   18.046   46.4    2.3   132   26.4 
2025-11-16 00:00 UT   17 39 15.4   -57 03 40    18.726   18.051   45.8    2.3   133   26.4 

    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.