C/2015 V4 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	30 Aug 2016	19.8	5.431 AU	6.183 AU	09h10m	-23°38'	38.7°	6.7°	216°
Nearest approach	28 Feb 2017	19.3	5.547 AU	4.715 AU	09h53m	-25°50'	144.0°	6.0°	23°
Today	18 Dec 2025	26.9	16.704 AU	17.204 AU	16h53m	+33°17'	58.0°	2.9°	346°

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. (8.5 + 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/2015 V4 (PANSTARRS) are:

    e (Eccentricity)                : 0.7053190
    q (Perihelion distance)         : 5.4314020
    i (Inclination)                 : 60.77430
    Ω (Longitude of ascending node) : 179.79540
    ω (Argument of perihelion)      : 306.77890
    L (Longitude of perihelion)     : 146.64443
    B (Latitude of perihelion)      : -44.34629
    T (Time of perihelion passage)  : 2457631.07230
    P (Orbital period in years)     : 79.13

    Epoch                           : 2025 Dec 17
    Reference                       : MPC104791

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-17 00:00 UT   16 52 31.5   +33 16 30    17.205   16.699   57.6    2.9   348   26.9 
2025-12-18 00:00 UT   16 52 50.7   +33 16 59    17.205   16.703   57.9    2.9   347   26.9 
2025-12-18 14:31 UT   16 53 02.3   +33 17 17    17.204   16.704   58.0    2.9   346   26.9 
2025-12-19 00:00 UT   16 53 09.9   +33 17 30    17.204   16.706   58.1    2.9   345   26.9 
2025-12-20 00:00 UT   16 53 29.0   +33 18 05    17.203   16.709   58.4    2.9   344   26.9 
2025-12-21 00:00 UT   16 53 48.0   +33 18 42    17.203   16.712   58.6    2.9   343   26.9 
2025-12-22 00:00 UT   16 54 07.0   +33 19 22    17.202   16.715   58.9    2.9   342   26.9 
2025-12-23 00:00 UT   16 54 25.9   +33 20 05    17.200   16.718   59.2    2.9   341   26.9 
2025-12-24 00:00 UT   16 54 44.7   +33 20 51    17.199   16.721   59.5    2.9   340   26.9 
2025-12-25 00:00 UT   16 55 03.5   +33 21 39    17.198   16.724   59.8    2.9   339   26.9 
2025-12-26 00:00 UT   16 55 22.1   +33 22 31    17.196   16.727   60.1    2.9   338   26.9 
2025-12-27 00:00 UT   16 55 40.7   +33 23 25    17.195   16.730   60.4    2.9   337   26.9 
2025-12-28 00:00 UT   16 55 59.2   +33 24 22    17.193   16.733   60.7    2.9   336   26.9 

    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.