C/2016 R2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	22 Dec 2017	11.6	2.973 AU	2.050 AU	04h34m	+10°59'	155.5°	7.9°	57°
Perihelion	9 May 2018	11.9	2.595 AU	3.270 AU	05h30m	+44°56'	41.0°	14.8°	60°
Today	13 Jul 2025	25.8	18.577 AU	17.773 AU	16h51m	-13°10'	141.2°	2.0°	109°

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.)

The orbital elements of C/2016 R2 (PANSTARRS) are:

            e (Eccentricity)                : 0.9946790
            q (Perihelion distance)         : 2.5945740
            i (Inclination)                 : 58.37140
            Ω (Longitude of ascending node) : 80.49850
            ω (Argument of perihelion)      : 33.08980
            L (Longitude of perihelion)     : 99.36514
            B (Latitude of perihelion)      : 27.70115
            T (Time of perihelion passage)  : 2458248.15790
            P (Orbital period in years)     : 10767.36

            Epoch                           : 2023 Sep 24
            Reference                       : MPEC 2021-N06

            Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)
        

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (7.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 4.35 + 5 log[∆] + 11.97 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-07-13 00:00 UT   16 51 17.0   -13 10 05    17.767   18.575  141.6    1.9   109   25.8 
2025-07-13 08:53 UT   16 51 13.3   -13 10 14    17.773   18.577  141.2    2.0   109   25.8 
2025-07-14 00:00 UT   16 51 07.1   -13 10 29    17.783   18.580  140.6    2.0   108   25.8 
2025-07-15 00:00 UT   16 50 57.5   -13 10 53    17.798   18.585  139.7    2.0   108   25.8 
2025-07-16 00:00 UT   16 50 48.0   -13 11 18    17.814   18.590  138.7    2.1   108   25.8 
2025-07-17 00:00 UT   16 50 38.6   -13 11 43    17.830   18.595  137.7    2.1   107   25.8 
2025-07-18 00:00 UT   16 50 29.5   -13 12 09    17.846   18.601  136.8    2.1   107   25.8 
2025-07-19 00:00 UT   16 50 20.5   -13 12 36    17.863   18.606  135.8    2.2   107   25.8 
2025-07-20 00:00 UT   16 50 11.6   -13 13 03    17.880   18.611  134.9    2.2   106   25.8 
2025-07-21 00:00 UT   16 50 02.9   -13 13 31    17.897   18.616  133.9    2.3   106   25.8 
2025-07-22 00:00 UT   16 49 54.4   -13 13 59    17.914   18.621  132.9    2.3   106   25.8 
2025-07-23 00:00 UT   16 49 46.1   -13 14 28    17.931   18.626  132.0    2.3   105   25.8 

    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.