C/2017 E3 (PANSTARRS)
ephemeris date magn radius delta ra dec elong phase PA
Nearest approach25 Apr 201716.25.909 AU5.048 AU 12h45m-41°46'146.0°5.5°39°
Perihelion6 Jun 201716.25.901 AU5.295 AU 12h37m-33°58'122.3°8.4°97°
Today3 Jan 202627.019.404 AU19.736 AU 19h01m+46°00'68.9°2.7°
C/2017 E3 (PANSTARRS)- 2026-01-03
astro.vanbuitenen.nl


 
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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 .9 + 5 log[∆] + 15.2 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/2017 E3 (PANSTARRS) are:

    e (Eccentricity)                : 1.0042480
    q (Perihelion distance)         : 5.9011030
    i (Inclination)                 : 70.66700
    Ω (Longitude of ascending node) : 220.76600
    ω (Argument of perihelion)      : 334.15210
    L (Longitude of perihelion)     : 211.65443
    B (Latitude of perihelion)      : -24.29273
    T (Time of perihelion passage)  : 2457911.24120

    Epoch                           : 2026 Jan 02
    Reference                       : MPEC 2022-O08

    Classification(s):              : Nearly isotropic; New (a > 10000 AU)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-01-02 00:00 UT   19 01 12.3   +46 00 35    19.728   19.399   69.0    2.7     3   27.0 
2026-01-03 00:00 UT   19 01 32.4   +46 00 52    19.735   19.403   68.9    2.7     2   27.0 
2026-01-03 02:16 UT   19 01 34.3   +46 00 54    19.736   19.404   68.9    2.7     2   27.0 
2026-01-04 00:00 UT   19 01 52.6   +46 01 11    19.741   19.408   68.8    2.7     1   27.0 
2026-01-05 00:00 UT   19 02 12.8   +46 01 34    19.748   19.413   68.7    2.7     0   27.0 
2026-01-06 00:00 UT   19 02 32.9   +46 01 58    19.754   19.417   68.6    2.7   359   27.0 
2026-01-07 00:00 UT   19 02 53.1   +46 02 26    19.760   19.422   68.5    2.7   358   27.0 
2026-01-08 00:00 UT   19 03 13.2   +46 02 56    19.766   19.427   68.4    2.7   357   27.0 
2026-01-09 00:00 UT   19 03 33.3   +46 03 30    19.772   19.431   68.3    2.7   356   27.0 
2026-01-10 00:00 UT   19 03 53.4   +46 04 05    19.778   19.436   68.3    2.7   355   27.0 
2026-01-11 00:00 UT   19 04 13.4   +46 04 44    19.784   19.440   68.2    2.7   354   27.0 
2026-01-12 00:00 UT   19 04 33.5   +46 05 25    19.790   19.445   68.1    2.7   353   27.0 
2026-01-13 00:00 UT   19 04 53.5   +46 06 09    19.795   19.450   68.1    2.7   352   27.0 



    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.