A/2020 H9
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	21 Dec 2019	22.4	2.560 AU	3.422 AU	16h52m	-44°23'	24.6°	9.2°	216°
Nearest approach	22 Apr 2020	21.2	2.872 AU	1.887 AU	14h32m	-24°30'	165.7°	5.0°	327°
Today	21 Mar 2026	29.6	16.765 AU	16.344 AU	09h37m	+60°43'	113.4°	3.1°	141°

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 displayed light curve is calculated under the assumption that the object remains inactive. (H=17.10; G=.15).

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 A/2020 H9 are:

    e (Eccentricity)                : 0.9922550
    q (Perihelion distance)         : 2.5597760
    i (Inclination)                 : 137.87130
    Ω (Longitude of ascending node) : 213.06650
    ω (Argument of perihelion)      : 312.54220
    L (Longitude of perihelion)     : 252.01033
    B (Latitude of perihelion)      : -29.61901
    T (Time of perihelion passage)  : 2458838.91560
    P (Orbital period in years)     : 6008.57

    Epoch                           : 2026 Mar 16
    Reference                       : MPEC 2026-E44

    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
2026-03-20 00:00 UT   09 38 03.5   +60 44 39    16.327   16.759  114.1    3.1   142   29.6 
2026-03-21 00:00 UT   09 37 37.6   +60 43 53    16.343   16.764  113.4    3.1   141   29.6 
2026-03-21 02:12 UT   09 37 35.2   +60 43 49    16.344   16.765  113.4    3.1   141   29.6 
2026-03-22 00:00 UT   09 37 12.1   +60 43 05    16.359   16.770  112.7    3.1   140   29.6 
2026-03-23 00:00 UT   09 36 47.0   +60 42 14    16.375   16.775  112.0    3.2   139   29.6 
2026-03-24 00:00 UT   09 36 22.2   +60 41 21    16.391   16.780  111.3    3.2   138   29.6 
2026-03-25 00:00 UT   09 35 57.9   +60 40 24    16.408   16.786  110.7    3.2   137   29.6 
2026-03-26 00:00 UT   09 35 33.9   +60 39 25    16.424   16.791  110.0    3.2   136   29.6 
2026-03-27 00:00 UT   09 35 10.4   +60 38 23    16.441   16.796  109.3    3.2   135   29.6 
2026-03-28 00:00 UT   09 34 47.2   +60 37 19    16.457   16.802  108.6    3.2   134   29.6 
2026-03-29 00:00 UT   09 34 24.5   +60 36 12    16.474   16.807  107.8    3.2   134   29.6 
2026-03-30 00:00 UT   09 34 02.2   +60 35 02    16.491   16.813  107.1    3.3   133   29.6 
2026-03-31 00:00 UT   09 33 40.3   +60 33 50    16.508   16.818  106.4    3.3   132   29.6 

    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.