C/2017 E3 (PANSTARRS)
ephemeris date magn radius delta ra dec elong phase PA
Nearest approach25 Apr 201716.25.942 AU5.079 AU12h47m-41°32'146.4°5.4°39°
Perihelion7 Jun 201716.35.935 AU5.329 AU12h39m-33°45'122.3°8.3°97°
Today7 Jul 202526.518.567 AU18.253 AU18h52m+50°56'106.4°3.0°177°
C/2017 E3 (PANSTARRS)- 2025-07-07
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.)

The orbital elements of C/2017 E3 (PANSTARRS) are:

            e (Eccentricity)                : 1.0056920
            q (Perihelion distance)         : 5.9345350
            i (Inclination)                 : 70.66520
            Ω (Longitude of ascending node) : 220.80610
            ω (Argument of perihelion)      : 334.43580
            L (Longitude of perihelion)     : 211.80655
            B (Latitude of perihelion)      : -24.02808
            T (Time of perihelion passage)  : 2457911.59990

            Epoch                           : 2022 Jul 23
            Reference                       : MPEC 2022-O08

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

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 (6.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently .89 + 5 log[∆] + 15.22 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
2025-07-07 00:00 UT   18 52 19.3   +50 56 42    18.253   18.566  106.4    3.0   177   26.5 
2025-07-07 02:51 UT   18 52 17.3   +50 56 42    18.253   18.567  106.4    3.0   177   26.5 
2025-07-08 00:00 UT   18 52 02.5   +50 56 41    18.256   18.571  106.5    3.0   176   26.5 
2025-07-09 00:00 UT   18 51 45.8   +50 56 37    18.260   18.575  106.5    3.0   175   26.5 
2025-07-10 00:00 UT   18 51 29.2   +50 56 29    18.264   18.580  106.6    3.0   174   26.5 
2025-07-11 00:00 UT   18 51 12.5   +50 56 19    18.268   18.585  106.6    3.0   173   26.5 
2025-07-12 00:00 UT   18 50 55.9   +50 56 05    18.272   18.589  106.7    3.0   172   26.5 
2025-07-13 00:00 UT   18 50 39.4   +50 55 49    18.276   18.594  106.7    3.0   171   26.5 
2025-07-14 00:00 UT   18 50 23.0   +50 55 29    18.280   18.599  106.8    3.0   170   26.5 
2025-07-15 00:00 UT   18 50 06.6   +50 55 05    18.284   18.603  106.8    3.0   169   26.5 
2025-07-16 00:00 UT   18 49 50.3   +50 54 39    18.288   18.608  106.8    3.0   168   26.5 
2025-07-17 00:00 UT   18 49 34.0   +50 54 10    18.293   18.613  106.8    3.0   167   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.