C/2016 R2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	22 Dec 2017	11.6	2.984 AU	2.064 AU	04h33m	+10°21'	155.0°	8.0°	56°
Perihelion	11 May 2018	11.9	2.594 AU	3.289 AU	05h33m	+44°52'	39.7°	14.4°	59°
Today	8 Nov 2025	26.2	19.186 AU	20.044 AU	16h54m	-14°40'	29.2°	1.4°	82°

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 4.3 + 5 log[∆] + 12.0 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/2016 R2 (PANSTARRS) are:

    e (Eccentricity)                : 0.9954390
    q (Perihelion distance)         : 2.5940620
    i (Inclination)                 : 58.38740
    Ω (Longitude of ascending node) : 80.47010
    ω (Argument of perihelion)      : 33.16840
    L (Longitude of perihelion)     : 99.38139
    B (Latitude of perihelion)      : 27.76966
    T (Time of perihelion passage)  : 2458250.34560
    P (Orbital period in years)     : 13563.77

    Epoch                           : 2025 Nov 07
    Reference                       : MPEC 2021-N06

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-11-07 00:00 UT   16 54 01.9   -14 39 40    20.028   19.180   30.4    1.5    83   26.2 
2025-11-08 00:00 UT   16 54 13.4   -14 40 29    20.041   19.185   29.5    1.5    82   26.2 
2025-11-08 05:31 UT   16 54 16.0   -14 40 40    20.044   19.186   29.2    1.4    82   26.2 
2025-11-09 00:00 UT   16 54 24.9   -14 41 16    20.054   19.190   28.5    1.4    82   26.2 
2025-11-10 00:00 UT   16 54 36.4   -14 42 04    20.067   19.195   27.6    1.4    81   26.2 
2025-11-11 00:00 UT   16 54 48.1   -14 42 51    20.079   19.200   26.7    1.3    81   26.2 
2025-11-12 00:00 UT   16 54 59.9   -14 43 38    20.091   19.205   25.8    1.3    80   26.2 
2025-11-13 00:00 UT   16 55 11.7   -14 44 25    20.103   19.211   24.9    1.2    79   26.2 
2025-11-14 00:00 UT   16 55 23.6   -14 45 11    20.115   19.216   24.0    1.2    78   26.2 
2025-11-15 00:00 UT   16 55 35.6   -14 45 57    20.126   19.221   23.1    1.2    78   26.2 
2025-11-16 00:00 UT   16 55 47.7   -14 46 42    20.138   19.226   22.2    1.1    77   26.2 
2025-11-17 00:00 UT   16 55 59.8   -14 47 28    20.148   19.231   21.3    1.1    76   26.2 
2025-11-18 00:00 UT   16 56 12.0   -14 48 12    20.159   19.236   20.4    1.0    75   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.