C/2020 S2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	12 Oct 2020	20.0	1.945 AU	1.029 AU	23h01m	+05°11'	147.3°	16.1°	84°
Perihelion	21 Dec 2020	20.2	1.766 AU	1.395 AU	00h33m	-07°56'	94.2°	33.8°	66°
Today	27 Dec 2025	33.2	11.939 AU	12.102 AU	12h59m	-08°40'	78.2°	4.6°	292°

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. (17.0 + 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/2020 S2 (PANSTARRS) are:

    e (Eccentricity)                : 0.8278050
    q (Perihelion distance)         : 1.7655660
    i (Inclination)                 : 22.36470
    Ω (Longitude of ascending node) : 197.71270
    ω (Argument of perihelion)      : 202.44170
    L (Longitude of perihelion)     : 218.61729
    B (Latitude of perihelion)      : -8.35196
    T (Time of perihelion passage)  : 2459205.32870
    P (Orbital period in years)     : 32.83

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2022-ST7

    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
2025-12-26 00:00 UT   12 59 21.5   -08 40 00    12.116   11.935   77.1    4.6   292   33.2 
2025-12-27 00:00 UT   12 59 27.8   -08 40 33    12.103   11.939   78.1    4.6   292   33.2 
2025-12-27 01:44 UT   12 59 28.3   -08 40 35    12.102   11.939   78.2    4.6   292   33.2 
2025-12-28 00:00 UT   12 59 33.8   -08 41 04    12.090   11.943   79.1    4.6   292   33.2 
2025-12-29 00:00 UT   12 59 39.5   -08 41 32    12.076   11.947   80.1    4.7   292   33.2 
2025-12-30 00:00 UT   12 59 44.9   -08 41 59    12.063   11.950   81.1    4.7   292   33.2 
2025-12-31 00:00 UT   12 59 49.9   -08 42 24    12.050   11.954   82.1    4.7   292   33.2 
2026-01-01 00:00 UT   12 59 54.7   -08 42 48    12.036   11.958   83.1    4.7   292   33.2 
2026-01-02 00:00 UT   12 59 59.1   -08 43 09    12.023   11.962   84.1    4.7   292   33.2 
2026-01-03 00:00 UT   13 00 03.3   -08 43 28    12.009   11.965   85.1    4.7   292   33.2 
2026-01-04 00:00 UT   13 00 07.1   -08 43 45    11.996   11.969   86.1    4.7   292   33.2 
2026-01-05 00:00 UT   13 00 10.6   -08 44 01    11.982   11.973   87.1    4.7   292   33.2 
2026-01-06 00:00 UT   13 00 13.8   -08 44 14    11.969   11.976   88.1    4.7   293   33.2 

    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.