C/2020 P4-A (SOHO)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	6 Aug 2020	8.3	0.126 AU	0.911 AU	09h22m	+18°45'	4.3°	142.9°	59°
Perihelion	8 Aug 2020	7.1	0.091 AU	0.943 AU	09h00m	+17°09'	3.3°	139.8°	288°
Today	8 Jun 2026	37.9	18.899 AU	18.967 AU	10h45m	+02°28'	84.6°	3.1°	113°

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 18.8 + 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-A (SOHO) are:

    e (Eccentricity)                : 1.0020940
    q (Perihelion distance)         : 0.0907350
    i (Inclination)                 : 26.33730
    Ω (Longitude of ascending node) : 175.20070
    ω (Argument of perihelion)      : 177.47990
    L (Longitude of perihelion)     : 172.94191
    B (Latitude of perihelion)      : 1.11776
    T (Time of perihelion passage)  : 2459069.72160

    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
2026-06-07 00:00 UT   10 45 55.7   +02 28 18    18.931   18.889   86.1    3.1   113   37.9 
2026-06-08 00:00 UT   10 45 57.4   +02 28 26    18.954   18.896   85.1    3.1   113   37.9 
2026-06-08 13:48 UT   10 45 58.4   +02 28 31    18.967   18.899   84.6    3.1   113   37.9 
2026-06-09 00:00 UT   10 45 59.3   +02 28 34    18.977   18.902   84.2    3.1   113   37.9 
2026-06-10 00:00 UT   10 46 01.3   +02 28 40    19.000   18.908   83.2    3.1   113   37.9 
2026-06-11 00:00 UT   10 46 03.6   +02 28 45    19.023   18.914   82.3    3.0   113   37.9 
2026-06-12 00:00 UT   10 46 06.0   +02 28 49    19.046   18.920   81.3    3.0   113   37.9 
2026-06-13 00:00 UT   10 46 08.7   +02 28 52    19.069   18.926   80.4    3.0   113   37.9 
2026-06-14 00:00 UT   10 46 11.5   +02 28 54    19.091   18.933   79.5    3.0   113   37.9 
2026-06-15 00:00 UT   10 46 14.4   +02 28 54    19.114   18.939   78.5    3.0   113   37.9 
2026-06-16 00:00 UT   10 46 17.6   +02 28 53    19.137   18.945   77.6    3.0   113   37.9 
2026-06-17 00:00 UT   10 46 21.0   +02 28 51    19.160   18.951   76.6    3.0   113   37.9 
2026-06-18 00:00 UT   10 46 24.5   +02 28 47    19.182   18.957   75.7    3.0   114   37.9 

    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.