C/2020 P4-C (SOHO)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	5 Aug 2020	7.0	0.090 AU	0.949 AU	09h14m	+19°05'	3.6°	134.9°	52°
Nearest approach	7 Aug 2020	8.6	0.137 AU	0.908 AU	08h48m	+17°05'	5.2°	138.0°	278°
Today	27 Dec 2025	39.5	25.852 AU	25.060 AU	06h10m	-13°47'	142.7°	1.3°	5°

This comet is a sunskirter. Although it may become very bright at perihelion, this will only be for a very short period very close to the sun.

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 18.4 + 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 P4-C (SOHO) are:

    e (Eccentricity)                : 1.0132730
    q (Perihelion distance)         : 0.0896070
    i (Inclination)                 : 37.27020
    Ω (Longitude of ascending node) : 165.26390
    ω (Argument of perihelion)      : 115.99210
    L (Longitude of perihelion)     : 106.75877
    B (Latitude of perihelion)      : 32.97844
    T (Time of perihelion passage)  : 2459066.93580

    Epoch                           : 2025 Dec 26
    Reference                       : MPEC 2020-QN1

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-26 00:00 UT   06 10 39.0   -13 48 02    25.044   25.836  142.8    1.3     3   39.5 
2025-12-27 00:00 UT   06 10 29.4   -13 47 53    25.058   25.850  142.8    1.3     4   39.5 
2025-12-27 03:21 UT   06 10 28.1   -13 47 51    25.060   25.852  142.7    1.3     5   39.5 
2025-12-28 00:00 UT   06 10 19.9   -13 47 42    25.073   25.864  142.7    1.3     6   39.5 
2025-12-29 00:00 UT   06 10 10.3   -13 47 30    25.088   25.878  142.6    1.3     8   39.5 
2025-12-30 00:00 UT   06 10 00.8   -13 47 17    25.103   25.892  142.5    1.3    10   39.5 
2025-12-31 00:00 UT   06 09 51.3   -13 47 02    25.118   25.906  142.4    1.3    11   39.5 
2026-01-01 00:00 UT   06 09 41.8   -13 46 45    25.134   25.920  142.2    1.3    13   39.5 
2026-01-02 00:00 UT   06 09 32.4   -13 46 27    25.150   25.934  142.0    1.3    15   39.5 
2026-01-03 00:00 UT   06 09 23.0   -13 46 08    25.166   25.948  141.8    1.3    16   39.5 
2026-01-04 00:00 UT   06 09 13.7   -13 45 47    25.182   25.962  141.6    1.3    18   39.5 
2026-01-05 00:00 UT   06 09 04.4   -13 45 24    25.199   25.976  141.3    1.4    20   39.5 
2026-01-06 00:00 UT   06 08 55.1   -13 45 00    25.215   25.990  141.1    1.4    21   39.5 

    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.