C/2020 H5 (Robinson)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	10 Dec 2020	19.7	9.334 AU	9.789 AU	12h34m	-36°32'	59.9°	5.2°	278°
Nearest approach	11 Apr 2021	19.4	9.360 AU	8.470 AU	12h24m	-34°27'	151.0°	3.0°	29°
Today	27 May 2026	22.2	14.225 AU	13.469 AU	15h29m	+20°14'	136.8°	2.8°	164°

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. (5.0 + 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 H5 (Robinson) are:

    e (Eccentricity)                : 0.9987980
    q (Perihelion distance)         : 9.3343530
    i (Inclination)                 : 70.20360
    Ω (Longitude of ascending node) : 210.59600
    ω (Argument of perihelion)      : 326.27180
    L (Longitude of perihelion)     : 197.85501
    B (Latitude of perihelion)      : -31.49603
    T (Time of perihelion passage)  : 2459193.73500
    P (Orbital period in years)     : 684336.38

    Epoch                           : 2026 May 27
    Reference                       : MPC194166

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-05-26 00:00 UT   15 29 55.1   +20 11 59    13.452   14.217  137.6    2.8   166   22.2 
2026-05-27 00:00 UT   15 29 41.3   +20 13 17    13.461   14.221  137.2    2.8   165   22.2 
2026-05-27 22:45 UT   15 29 28.2   +20 14 29    13.469   14.225  136.8    2.8   164   22.2 
2026-05-28 00:00 UT   15 29 27.5   +20 14 32    13.470   14.225  136.7    2.8   163   22.2 
2026-05-29 00:00 UT   15 29 13.7   +20 15 45    13.479   14.229  136.3    2.8   162   22.2 
2026-05-30 00:00 UT   15 29 00.1   +20 16 54    13.488   14.233  135.8    2.8   161   22.2 
2026-05-31 00:00 UT   15 28 46.5   +20 18 00    13.498   14.236  135.3    2.9   160   22.2 
2026-06-01 00:00 UT   15 28 33.0   +20 19 03    13.507   14.240  134.8    2.9   158   22.2 
2026-06-02 00:00 UT   15 28 19.7   +20 20 04    13.517   14.244  134.3    2.9   157   22.2 
2026-06-03 00:00 UT   15 28 06.4   +20 21 01    13.528   14.248  133.7    2.9   156   22.2 
2026-06-04 00:00 UT   15 27 53.3   +20 21 55    13.538   14.251  133.2    3.0   155   22.2 
2026-06-05 00:00 UT   15 27 40.2   +20 22 46    13.549   14.255  132.6    3.0   154   22.2 
2026-06-06 00:00 UT   15 27 27.3   +20 23 34    13.559   14.259  132.0    3.0   152   22.2 

    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.