C/2020 H6 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	30 Apr 2021	15.6	4.853 AU	3.853 AU	13h59m	-12°27'	172.3°	1.6°	108°
Perihelion	30 Sep 2021	16.2	4.700 AU	5.542 AU	14h21m	+03°39'	29.8°	6.1°	78°
Today	9 May 2025	21.5	10.514 AU	10.946 AU	22h44m	+58°09'	62.2°	4.9°	282°

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 H6 (ATLAS) are:

            e (Eccentricity)                : 0.9984330
            q (Perihelion distance)         : 4.6996370
            i (Inclination)                 : 79.97870
            Ω (Longitude of ascending node) : 213.71630
            ω (Argument of perihelion)      : 20.24510
            L (Longitude of perihelion)     : 217.38853
            B (Latitude of perihelion)      : 19.92302
            T (Time of perihelion passage)  : 2459487.62440
            P (Orbital period in years)     : 164245.31

            Epoch                           : 2024 Jun 06
            Reference                       : MPEC 2024-KD0

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

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 (8.00 + 5 log[∆] + 8.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 5.08 + 5 log[∆] + 11.03 log[r]).

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
2025-05-09 00:00 UT   22 44 25.7   +58 08 48    10.946   10.513   62.1    4.9   282   21.5 
2025-05-09 05:38 UT   22 44 31.2   +58 09 46    10.946   10.514   62.2    4.9   282   21.5 
2025-05-10 00:00 UT   22 44 48.9   +58 12 56    10.948   10.518   62.4    4.9   281   21.6 
2025-05-11 00:00 UT   22 45 11.6   +58 17 05    10.949   10.524   62.6    4.9   281   21.6 
2025-05-12 00:00 UT   22 45 33.8   +58 21 15    10.951   10.529   62.9    4.9   280   21.6 
2025-05-13 00:00 UT   22 45 55.5   +58 25 25    10.952   10.535   63.1    4.9   279   21.6 
2025-05-14 00:00 UT   22 46 16.7   +58 29 35    10.953   10.540   63.4    4.9   278   21.6 
2025-05-15 00:00 UT   22 46 37.3   +58 33 46    10.955   10.546   63.7    4.9   277   21.6 
2025-05-16 00:00 UT   22 46 57.3   +58 37 57    10.956   10.552   64.0    4.9   276   21.6 
2025-05-17 00:00 UT   22 47 16.9   +58 42 09    10.957   10.557   64.3    4.9   275   21.6 
2025-05-18 00:00 UT   22 47 35.9   +58 46 21    10.957   10.563   64.5    5.0   274   21.6 
2025-05-19 00:00 UT   22 47 54.3   +58 50 33    10.958   10.568   64.8    5.0   273   21.6 

    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.