C/2020 P4-C (SOHO)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	6 Aug 2020	6.9	0.087 AU	0.952 AU	09h19m	+18°34'	3.5°	134.0°	54°
Nearest approach	8 Aug 2020	8.6	0.138 AU	0.908 AU	08h53m	+16°25'	5.3°	137.4°	274°
Today	31 Oct 2025	39.3	25.133 AU	24.685 AU	06h18m	-13°17'	115.7°	2.0°	293°

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)                : 1.0128670
    q (Perihelion distance)         : 0.0865840
    i (Inclination)                 : 37.45880
    Ω (Longitude of ascending node) : 164.02940
    ω (Argument of perihelion)      : 116.74790
    L (Longitude of perihelion)     : 106.44177
    B (Latitude of perihelion)      : 32.89571
    T (Time of perihelion passage)  : 2459068.30060

    Epoch                           : 2021 Feb 13
    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
2025-10-30 00:00 UT   06 18 20.8   -13 16 01    24.681   25.109  114.3    2.1   292   39.3 
2025-10-31 00:00 UT   06 18 15.4   -13 17 09    24.683   25.122  115.1    2.1   293   39.3 
2025-10-31 17:31 UT   06 18 11.3   -13 17 57    24.685   25.133  115.7    2.0   293   39.3 
2025-11-01 00:00 UT   06 18 09.7   -13 18 15    24.685   25.136  115.9    2.0   293   39.3 
2025-11-02 00:00 UT   06 18 04.0   -13 19 21    24.688   25.150  116.6    2.0   294   39.3 
2025-11-03 00:00 UT   06 17 58.1   -13 20 26    24.690   25.164  117.4    2.0   295   39.4 
2025-11-04 00:00 UT   06 17 52.0   -13 21 29    24.693   25.178  118.1    2.0   296   39.4 
2025-11-05 00:00 UT   06 17 45.8   -13 22 32    24.696   25.192  118.9    2.0   297   39.4 
2025-11-06 00:00 UT   06 17 39.5   -13 23 34    24.699   25.206  119.6    2.0   297   39.4 
2025-11-07 00:00 UT   06 17 33.1   -13 24 35    24.702   25.220  120.4    1.9   298   39.4 
2025-11-08 00:00 UT   06 17 26.5   -13 25 35    24.706   25.234  121.1    1.9   299   39.4 
2025-11-09 00:00 UT   06 17 19.8   -13 26 33    24.709   25.248  121.8    1.9   300   39.4 
2025-11-10 00:00 UT   06 17 13.0   -13 27 31    24.713   25.262  122.6    1.9   301   39.4 

    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.