C/2016 R2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	22 Dec 2017	11.6	2.988 AU	2.068 AU	04h33m	+10°24'	155.0°	8.0°	56°
Perihelion	12 May 2018	11.9	2.598 AU	3.295 AU	05h34m	+44°53'	39.6°	14.4°	59°
Today	7 Jul 2026	26.5	20.403 AU	19.524 AU	16h56m	-15°13'	149.0°	1.5°	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.)

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)                : 0.9955970
    q (Perihelion distance)         : 2.5975100
    i (Inclination)                 : 58.37680
    Ω (Longitude of ascending node) : 80.49290
    ω (Argument of perihelion)      : 33.18190
    L (Longitude of perihelion)     : 99.41851
    B (Latitude of perihelion)      : 27.77710
    T (Time of perihelion passage)  : 2458250.60340
    P (Orbital period in years)     : 14328.90

    Epoch                           : 2026 Jul 06
    Reference                       : MPC194149

    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
2026-07-06 00:00 UT   16 57 10.3   -15 13 29    19.506   20.396  150.3    1.4   109   26.5 
2026-07-07 00:00 UT   16 57 00.2   -15 13 41    19.519   20.401  149.3    1.5   109   26.5 
2026-07-07 08:39 UT   16 56 56.6   -15 13 46    19.524   20.403  149.0    1.5   109   26.5 
2026-07-08 00:00 UT   16 56 50.3   -15 13 55    19.533   20.406  148.4    1.5   108   26.5 
2026-07-09 00:00 UT   16 56 40.4   -15 14 09    19.546   20.411  147.4    1.5   108   26.5 
2026-07-10 00:00 UT   16 56 30.7   -15 14 23    19.560   20.416  146.4    1.6   108   26.5 
2026-07-11 00:00 UT   16 56 21.0   -15 14 38    19.575   20.421  145.5    1.6   107   26.5 
2026-07-12 00:00 UT   16 56 11.5   -15 14 53    19.589   20.426  144.5    1.7   107   26.5 
2026-07-13 00:00 UT   16 56 02.2   -15 15 09    19.604   20.431  143.5    1.7   106   26.5 
2026-07-14 00:00 UT   16 55 53.0   -15 15 25    19.619   20.436  142.6    1.7   106   26.5 
2026-07-15 00:00 UT   16 55 43.9   -15 15 41    19.634   20.441  141.6    1.8   106   26.5 
2026-07-16 00:00 UT   16 55 34.9   -15 15 59    19.649   20.446  140.6    1.8   105   26.5 
2026-07-17 00:00 UT   16 55 26.1   -15 16 16    19.665   20.451  139.7    1.8   105   26.5 

    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.