C/2021 A6 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	3 Mar 2021	20.2	7.935 AU	6.968 AU	10h28m	-04°49'	166.3°	1.7°	34°
Perihelion	3 May 2021	20.4	7.926 AU	7.493 AU	10h15m	+01°40'	112.0°	6.8°	108°
Today	25 Dec 2025	23.5	12.645 AU	12.768 AU	15h22m	+47°16'	80.6°	4.4°	321°

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. (7.0 + 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/2021 A6 (PANSTARRS) are:

    e (Eccentricity)                : 0.9995300
    q (Perihelion distance)         : 7.9261220
    i (Inclination)                 : 75.55660
    Ω (Longitude of ascending node) : 164.00970
    ω (Argument of perihelion)      : 351.64660
    L (Longitude of perihelion)     : 161.91221
    B (Latitude of perihelion)      : -8.08759
    T (Time of perihelion passage)  : 2459337.82860

    Epoch                           : 2025 Dec 24
    Reference                       : MPEC 2024-P23

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-24 00:00 UT   15 21 46.3   +47 13 17    12.773   12.640   80.0    4.4   322   23.5 
2025-12-25 00:00 UT   15 22 14.9   +47 16 08    12.769   12.644   80.5    4.4   321   23.5 
2025-12-25 05:47 UT   15 22 21.7   +47 16 50    12.768   12.645   80.6    4.4   321   23.5 
2025-12-26 00:00 UT   15 22 43.2   +47 19 02    12.766   12.648   80.9    4.4   320   23.6 
2025-12-27 00:00 UT   15 23 11.2   +47 21 60    12.762   12.653   81.4    4.4   319   23.6 
2025-12-28 00:00 UT   15 23 39.0   +47 25 01    12.759   12.657   81.8    4.4   318   23.6 
2025-12-29 00:00 UT   15 24 06.6   +47 28 05    12.756   12.661   82.3    4.4   318   23.6 
2025-12-30 00:00 UT   15 24 33.9   +47 31 13    12.752   12.665   82.7    4.4   317   23.6 
2025-12-31 00:00 UT   15 25 00.9   +47 34 23    12.749   12.669   83.1    4.4   316   23.6 
2026-01-01 00:00 UT   15 25 27.7   +47 37 37    12.745   12.673   83.6    4.4   315   23.6 
2026-01-02 00:00 UT   15 25 54.2   +47 40 55    12.742   12.678   84.0    4.4   314   23.6 
2026-01-03 00:00 UT   15 26 20.4   +47 44 15    12.738   12.682   84.5    4.4   313   23.6 
2026-01-04 00:00 UT   15 26 46.3   +47 47 38    12.735   12.686   84.9    4.4   313   23.6 

    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.