C/2021 A6 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	3 Mar 2021	20.2	7.937 AU	6.970 AU	10h28m	-04°48'	166.4°	1.7°	34°
Perihelion	3 May 2021	20.4	7.928 AU	7.499 AU	10h15m	+01°42'	111.7°	6.8°	108°
Today	18 May 2026	23.8	13.253 AU	12.963 AU	15h23m	+55°49'	104.5°	4.2°	176°

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)                : 0.9997150
    q (Perihelion distance)         : 7.9279500
    i (Inclination)                 : 75.55220
    Ω (Longitude of ascending node) : 163.99810
    ω (Argument of perihelion)      : 351.67030
    L (Longitude of perihelion)     : 161.90602
    B (Latitude of perihelion)      : -8.06449
    T (Time of perihelion passage)  : 2459338.10910

    Epoch                           : 2026 May 17
    Reference                       : MPEC 2026-E44

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-05-17 00:00 UT   15 23 58.3   +55 49 20    12.949   13.246  105.0    4.2   178   23.8 
2026-05-18 00:00 UT   15 23 36.6   +55 49 45    12.957   13.250  104.7    4.2   177   23.8 
2026-05-18 16:42 UT   15 23 21.6   +55 49 60    12.963   13.253  104.5    4.2   176   23.8 
2026-05-19 00:00 UT   15 23 15.0   +55 50 05    12.966   13.254  104.4    4.2   176   23.8 
2026-05-20 00:00 UT   15 22 53.5   +55 50 21    12.975   13.259  104.2    4.2   174   23.8 
2026-05-21 00:00 UT   15 22 32.0   +55 50 32    12.983   13.263  103.9    4.2   173   23.8 
2026-05-22 00:00 UT   15 22 10.6   +55 50 39    12.992   13.267  103.6    4.3   172   23.8 
2026-05-23 00:00 UT   15 21 49.3   +55 50 40    13.001   13.271  103.3    4.3   171   23.8 
2026-05-24 00:00 UT   15 21 28.2   +55 50 38    13.010   13.276  103.0    4.3   170   23.8 
2026-05-25 00:00 UT   15 21 07.1   +55 50 30    13.019   13.280  102.7    4.3   169   23.8 
2026-05-26 00:00 UT   15 20 46.2   +55 50 18    13.029   13.284  102.4    4.3   168   23.8 
2026-05-27 00:00 UT   15 20 25.4   +55 50 01    13.038   13.288  102.1    4.3   167   23.8 
2026-05-28 00:00 UT   15 20 04.8   +55 49 40    13.047   13.292  101.8    4.3   166   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.