C/2021 P2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	2 Sep 2022	19.3	5.180 AU	4.292 AU	21h42m	+19°36'	148.5°	5.8°	150°
Perihelion	22 Jan 2023	19.9	5.064 AU	5.918 AU	20h40m	+07°08'	27.4°	5.1°	12°
Today	7 Sep 2026	24.5	10.528 AU	11.104 AU	14h27m	-09°00'	53.0°	4.4°	105°

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. (9.0 + 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 P2 (PANSTARRS) are:

    e (Eccentricity)                : 0.9993300
    q (Perihelion distance)         : 5.0639340
    i (Inclination)                 : 150.03710
    Ω (Longitude of ascending node) : 32.10640
    ω (Argument of perihelion)      : 76.66800
    L (Longitude of perihelion)     : 317.40477
    B (Latitude of perihelion)      : 29.07666
    T (Time of perihelion passage)  : 2459967.30450
    P (Orbital period in years)     : 657082.42

    Epoch                           : 2026 Sep 06
    Reference                       : MPC194175

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-09-06 00:00 UT   14 26 54.5   -08 57 58    11.074   10.520   54.4    4.5   105   24.4 
2026-09-07 00:00 UT   14 27 00.4   -08 59 42    11.093   10.525   53.5    4.4   105   24.4 
2026-09-07 13:48 UT   14 27 03.9   -09 00 42    11.104   10.528   53.0    4.4   105   24.5 
2026-09-08 00:00 UT   14 27 06.5   -09 01 27    11.112   10.531   52.6    4.4   105   24.5 
2026-09-09 00:00 UT   14 27 12.9   -09 03 13    11.131   10.536   51.6    4.3   105   24.5 
2026-09-10 00:00 UT   14 27 19.5   -09 04 59    11.150   10.541   50.7    4.2   104   24.5 
2026-09-11 00:00 UT   14 27 26.4   -09 06 46    11.168   10.547   49.8    4.2   104   24.5 
2026-09-12 00:00 UT   14 27 33.5   -09 08 34    11.187   10.552   48.9    4.1   104   24.5 
2026-09-13 00:00 UT   14 27 40.9   -09 10 22    11.205   10.558   47.9    4.1   104   24.5 
2026-09-14 00:00 UT   14 27 48.5   -09 12 11    11.223   10.563   47.0    4.0   104   24.5 
2026-09-15 00:00 UT   14 27 56.3   -09 14 01    11.241   10.568   46.1    3.9   104   24.5 
2026-09-16 00:00 UT   14 28 04.4   -09 15 51    11.259   10.574   45.1    3.9   104   24.5 
2026-09-17 00:00 UT   14 28 12.7   -09 17 41    11.276   10.579   44.2    3.8   103   24.5 

    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.