C/2020 H3 (Wierzchos)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	5 Jun 2020	17.7	2.300 AU	1.653 AU	20h06m	+19°31'	117.2°	23.1°	230°
Nearest approach	21 Jun 2020	17.7	2.307 AU	1.614 AU	19h50m	+29°26'	120.9°	22.2°	210°
Today	2 Dec 2025	30.7	15.525 AU	14.595 AU	05h33m	+37°17'	159.9°	1.3°	224°

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. (13.0 + 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 H3 (Wierzchos) are:

    e (Eccentricity)                : 1.0000000
    q (Perihelion distance)         : 2.3002880
    i (Inclination)                 : 62.52920
    Ω (Longitude of ascending node) : 270.62270
    ω (Argument of perihelion)      : 30.44560
    L (Longitude of perihelion)     : 285.79286
    B (Latitude of perihelion)      : 26.71708
    T (Time of perihelion passage)  : 2459006.21610

    Epoch                           : 
    Reference                       : MPEC 2020-HM1

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-01 00:00 UT   05 34 02.0   +37 18 26    14.593   15.517  158.9    1.3   227   30.7 
2025-12-02 00:00 UT   05 33 43.4   +37 18 00    14.594   15.523  159.7    1.3   225   30.7 
2025-12-02 06:35 UT   05 33 38.2   +37 17 53    14.595   15.525  159.9    1.3   224   30.7 
2025-12-03 00:00 UT   05 33 24.6   +37 17 33    14.596   15.529  160.4    1.2   223   30.7 
2025-12-04 00:00 UT   05 33 05.8   +37 17 05    14.598   15.534  161.2    1.2   220   30.7 
2025-12-05 00:00 UT   05 32 46.9   +37 16 35    14.600   15.540  161.9    1.1   218   30.7 
2025-12-06 00:00 UT   05 32 28.0   +37 16 04    14.603   15.546  162.5    1.1   215   30.7 
2025-12-07 00:00 UT   05 32 09.0   +37 15 32    14.605   15.551  163.2    1.1   212   30.7 
2025-12-08 00:00 UT   05 31 49.9   +37 14 59    14.609   15.557  163.7    1.0   209   30.7 
2025-12-09 00:00 UT   05 31 30.8   +37 14 25    14.612   15.563  164.3    1.0   205   30.7 
2025-12-10 00:00 UT   05 31 11.7   +37 13 49    14.616   15.569  164.7    1.0   202   30.7 
2025-12-11 00:00 UT   05 30 52.6   +37 13 12    14.620   15.574  165.1    0.9   198   30.7 
2025-12-12 00:00 UT   05 30 33.5   +37 12 34    14.624   15.580  165.5    0.9   194   30.8 

    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.