Skip Navigation Links

C/2025 A4 (PANSTARRS)
ephemeris date magn radius delta ra dec elong phase PA
Perihelion13 Jan 202521.03.825 AU3.543 AU 13h40m+26°17'99.2°14.7°289°
Nearest approach28 Mar 202520.73.861 AU3.023 AU 13h40m+30°36'142.3°9.1°209°
Today12 Sep 202623.75.575 AU5.807 AU 15h54m-20°46'71.8°9.9°102°
C/2025 A4 (PANSTARRS)- 2026-09-12
astro.vanbuitenen.nl


 
-1 month
-1 week
-1 day
Now
+1 day
+1 week
+1 month

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. (12.4 + 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/2025 A4 (PANSTARRS) are: 

    e (Eccentricity)                : 0.6546320
    q (Perihelion distance)         : 3.8249320
    i (Inclination)                 : 32.01900
    Ω (Longitude of ascending node) : 69.91710
    ω (Argument of perihelion)      : 102.83670
    L (Longitude of perihelion)     : 354.96005
    B (Latitude of perihelion)      : 31.12784
    T (Time of perihelion passage)  : 2460688.96700
    P (Orbital period in years)     : 36.86

    Epoch                           : 2026 Sep 11
    Reference                       : MPC194193

    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
2026-09-11 00:00 UT   15 53 44.3   -20 42 32     5.785    5.571   72.8    9.9   102   23.7 
2026-09-12 00:00 UT   15 54 13.6   -20 46 25     5.805    5.575   71.9    9.9   102   23.7 
2026-09-12 02:44 UT   15 54 17.0   -20 46 52     5.807    5.575   71.8    9.9   102   23.7 
2026-09-13 00:00 UT   15 54 43.5   -20 50 19     5.824    5.579   71.1    9.8   102   23.7 
2026-09-14 00:00 UT   15 55 13.8   -20 54 12     5.843    5.584   70.2    9.8   102   23.7 
2026-09-15 00:00 UT   15 55 44.7   -20 58 06     5.862    5.588   69.4    9.7   102   23.7 
2026-09-16 00:00 UT   15 56 16.0   -21 01 59     5.881    5.592   68.5    9.6   102   23.7 
2026-09-17 00:00 UT   15 56 47.9   -21 05 53     5.900    5.597   67.7    9.6   102   23.7 
2026-09-18 00:00 UT   15 57 20.2   -21 09 47     5.919    5.601   66.9    9.5   102   23.7 
2026-09-19 00:00 UT   15 57 53.0   -21 13 41     5.938    5.606   66.0    9.4   102   23.8 
2026-09-20 00:00 UT   15 58 26.2   -21 17 35     5.957    5.610   65.2    9.4   102   23.8 
2026-09-21 00:00 UT   15 58 60.0   -21 21 29     5.975    5.614   64.3    9.3   102   23.8 
2026-09-22 00:00 UT   15 59 34.1   -21 25 23     5.994    5.619   63.5    9.2   102   23.8 




    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.

Privacy policy