C/2020 P3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	7 Dec 2020	18.4	6.877 AU	6.392 AU	00h47m	+83°00'	115.7°	7.4°	114°
Perihelion	23 Apr 2021	18.6	6.818 AU	7.124 AU	04h05m	+79°15'	68.4°	7.9°	32°
Today	9 Dec 2025	22.5	12.444 AU	12.894 AU	13h20m	+03°37'	60.9°	4.0°	299°

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. (6.0 + 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 P3 (ATLAS) are:

    e (Eccentricity)                : 1.0038980
    q (Perihelion distance)         : 6.8175010
    i (Inclination)                 : 61.84120
    Ω (Longitude of ascending node) : 19.48850
    ω (Argument of perihelion)      : 82.36610
    L (Longitude of perihelion)     : 93.63324
    B (Latitude of perihelion)      : 60.90670
    T (Time of perihelion passage)  : 2459327.64950

    Epoch                           : 2025 Dec 08
    Reference                       : MPEC 2024-JU4

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-08 00:00 UT   13 20 12.4   +03 40 24    12.910   12.437   59.3    3.9   299   22.5 
2025-12-09 00:00 UT   13 20 22.5   +03 38 54    12.900   12.442   60.3    3.9   299   22.5 
2025-12-09 15:19 UT   13 20 28.9   +03 37 58    12.894   12.444   60.9    4.0   299   22.5 
2025-12-10 00:00 UT   13 20 32.4   +03 37 27    12.890   12.446   61.2    4.0   299   22.5 
2025-12-11 00:00 UT   13 20 42.1   +03 36 01    12.880   12.451   62.2    4.0   298   22.5 
2025-12-12 00:00 UT   13 20 51.6   +03 34 38    12.869   12.455   63.1    4.0   298   22.5 
2025-12-13 00:00 UT   13 21 00.8   +03 33 16    12.859   12.460   64.1    4.1   298   22.5 
2025-12-14 00:00 UT   13 21 09.7   +03 31 56    12.848   12.465   65.0    4.1   298   22.5 
2025-12-15 00:00 UT   13 21 18.4   +03 30 39    12.838   12.469   66.0    4.1   297   22.5 
2025-12-16 00:00 UT   13 21 26.9   +03 29 23    12.827   12.474   66.9    4.2   297   22.5 
2025-12-17 00:00 UT   13 21 35.1   +03 28 09    12.816   12.479   67.9    4.2   297   22.5 
2025-12-18 00:00 UT   13 21 43.1   +03 26 57    12.805   12.483   68.8    4.2   297   22.5 
2025-12-19 00:00 UT   13 21 50.8   +03 25 47    12.793   12.488   69.8    4.2   296   22.5 

    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.