C/2017 Y2 (PANSTARRS)
ephemeris date magn radius delta ra dec elong phase PA
Perihelion4 Nov 202016.94.619 AU5.312 AU 17h20m-01°46'41.7°8.2°68°
Nearest approach24 May 202116.54.889 AU3.885 AU 16h39m-17°06'171.3°1.8°243°
Today21 Oct 202525.313.265 AU13.853 AU 10h34m-42°22'52.1°3.4°247°
C/2017 Y2 (PANSTARRS)- 2025-10-21
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 4.0 + 5 log[∆] + 13.9 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 Y2 (PANSTARRS) are:

    e (Eccentricity)                : 1.0008830
    q (Perihelion distance)         : 4.6190070
    i (Inclination)                 : 128.44650
    Ω (Longitude of ascending node) : 66.02320
    ω (Argument of perihelion)      : 147.77430
    L (Longitude of perihelion)     : 87.42578
    B (Latitude of perihelion)      : 24.68569
    T (Time of perihelion passage)  : 2459158.31240

    Epoch                           : 2025 Oct 20
    Reference                       : MPEC 2024-DC6

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-10-20 00:00 UT   10 34 01.1   -42 16 37    13.853   13.254   51.4    3.4   245   25.3 
2025-10-21 00:00 UT   10 34 09.1   -42 19 40    13.853   13.260   51.7    3.4   246   25.3 
2025-10-21 22:05 UT   10 34 16.2   -42 22 29    13.853   13.265   52.1    3.4   247   25.3 
2025-10-22 00:00 UT   10 34 16.8   -42 22 44    13.853   13.265   52.1    3.4   247   25.3 
2025-10-23 00:00 UT   10 34 24.2   -42 25 49    13.852   13.271   52.5    3.4   248   25.3 
2025-10-24 00:00 UT   10 34 31.4   -42 28 56    13.852   13.276   52.9    3.4   250   25.3 
2025-10-25 00:00 UT   10 34 38.2   -42 32 04    13.851   13.281   53.3    3.4   251   25.3 
2025-10-26 00:00 UT   10 34 44.8   -42 35 13    13.850   13.287   53.7    3.5   252   25.3 
2025-10-27 00:00 UT   10 34 51.0   -42 38 23    13.849   13.292   54.2    3.5   253   25.3 
2025-10-28 00:00 UT   10 34 57.0   -42 41 34    13.848   13.298   54.6    3.5   254   25.3 
2025-10-29 00:00 UT   10 35 02.6   -42 44 46    13.846   13.303   55.1    3.5   255   25.3 
2025-10-30 00:00 UT   10 35 07.9   -42 47 60    13.845   13.308   55.5    3.5   256   25.3 
2025-10-31 00:00 UT   10 35 13.0   -42 51 14    13.843   13.314   56.0    3.5   257   25.3 



    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.