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	14 May 2025	25.6	18.267 AU	17.339 AU	17h03m	-13°03'	156.0°	1.3°	253°

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
2025-05-14 00:00 UT   17 03 25.5   -13 03 55    17.340   18.263  155.2    1.3   254   25.6 
2025-05-14 19:31 UT   17 03 15.8   -13 03 48    17.339   18.267  156.0    1.3   253   25.6 
2025-05-15 00:00 UT   17 03 13.6   -13 03 47    17.339   18.268  156.1    1.3   253   25.6 
2025-05-16 00:00 UT   17 03 01.6   -13 03 39    17.337   18.273  157.1    1.2   252   25.6 
2025-05-17 00:00 UT   17 02 49.5   -13 03 31    17.337   18.279  158.0    1.2   251   25.6 
2025-05-18 00:00 UT   17 02 37.3   -13 03 24    17.336   18.284  158.9    1.1   250   25.6 
2025-05-19 00:00 UT   17 02 25.1   -13 03 17    17.336   18.289  159.8    1.1   248   25.6 
2025-05-20 00:00 UT   17 02 12.7   -13 03 10    17.336   18.294  160.7    1.0   247   25.6 
2025-05-21 00:00 UT   17 02 00.3   -13 03 04    17.336   18.299  161.5    1.0   245   25.6 
2025-05-22 00:00 UT   17 01 47.9   -13 02 59    17.337   18.305  162.4    1.0   243   25.6 
2025-05-23 00:00 UT   17 01 35.3   -13 02 53    17.338   18.310  163.2    0.9   241   25.6 
2025-05-24 00:00 UT   17 01 22.7   -13 02 49    17.339   18.315  164.0    0.9   239   25.7 

    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.