C/2020 P4-A (SOHO)
ephemeris date magn radius delta ra dec elong phase PA
Nearest approach6 Aug 20205.70.126 AU0.911 AU09h22m+18°45'4.3°142.9°59°
Perihelion8 Aug 20204.60.091 AU0.943 AU09h00m+17°09'3.3°139.8°288°
Today28 Mar 202433.013.612 AU12.710 AU10h44m+01°32'153.6°1.9°100°
C/2020 P4-A (SOHO)- 2024-03-28
astro.vanbuitenen.nl


 
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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.)

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)
        

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (5.30 + 5 log[∆] + 15.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 16.15 + 5 log[∆] + 10.00 log[r]). The additional green curve shows the effect of forward scattering, occurring when the comet is between the earth and the sun, for a gas-to-dust light ratio δ90 of 0.30. (See Marcus 2007)


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.
A more printer-friendly version of the same chart can be found further down this page as well.


The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.


A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.



Ephemerides:
Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2024-03-28 00:00 UT   10 44 47.9   +01 31 59    12.705   13.609  154.0    1.8   100   33.0 
2024-03-28 09:22 UT   10 44 42.2   +01 32 41    12.710   13.612  153.6    1.9   100   33.0 
2024-03-29 00:00 UT   10 44 33.4   +01 33 46    12.719   13.616  152.9    1.9   100   33.0 
2024-03-30 00:00 UT   10 44 19.1   +01 35 32    12.733   13.623  151.9    2.0   101   33.0 
2024-03-31 00:00 UT   10 44 04.9   +01 37 18    12.748   13.630  150.9    2.0   101   33.0 
2024-04-01 00:00 UT   10 43 50.9   +01 39 03    12.763   13.637  149.8    2.1   102   33.0 
2024-04-02 00:00 UT   10 43 37.2   +01 40 47    12.779   13.644  148.8    2.2   102   33.0 
2024-04-03 00:00 UT   10 43 23.6   +01 42 31    12.794   13.651  147.8    2.2   103   33.0 
2024-04-04 00:00 UT   10 43 10.2   +01 44 14    12.810   13.658  146.8    2.3   103   33.0 
2024-04-05 00:00 UT   10 42 57.0   +01 45 56    12.827   13.666  145.7    2.4   103   33.1 
2024-04-06 00:00 UT   10 42 44.0   +01 47 37    12.843   13.673  144.7    2.4   104   33.1 
2024-04-07 00:00 UT   10 42 31.2   +01 49 17    12.860   13.680  143.7    2.5   104   33.1 


    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.