C/2020 Y3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	3 Dec 2020	17.5	1.993 AU	2.587 AU	13h28m	-24°05'	43.6°	19.9°	277°
Nearest approach	10 Mar 2021	17.1	2.309 AU	1.594 AU	14h59m	+23°06'	124.7°	20.7°	258°
Today	25 Apr 2024	28.1	10.918 AU	11.261 AU	21h33m	+55°35'	67.6°	4.9°	279°

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 Y3 (ATLAS) are:

            e (Eccentricity)                : 0.9857050
            q (Perihelion distance)         : 1.9930880
            i (Inclination)                 : 83.11000
            Ω (Longitude of ascending node) : 191.41610
            ω (Argument of perihelion)      : 341.89050
            L (Longitude of perihelion)     : 189.16942
            B (Latitude of perihelion)      : -17.97423
            T (Time of perihelion passage)  : 2459186.75440
            P (Orbital period in years)     : 1646.32

            Epoch                           : 2024 Apr 24
            Reference                       : MPEC 2021-R75

            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 (13.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 12.45 + 5 log[∆] + 10.00 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
2024-04-25 00:00 UT   21 33 11.4   +55 34 13    11.260   10.916   67.6    4.9   280   28.1 
2024-04-25 07:35 UT   21 33 15.9   +55 35 35    11.261   10.918   67.6    4.9   279   28.1 
2024-04-26 00:00 UT   21 33 25.7   +55 38 34    11.263   10.923   67.8    4.9   279   28.1 
2024-04-27 00:00 UT   21 33 39.4   +55 42 56    11.265   10.929   68.0    4.9   278   28.1 
2024-04-28 00:00 UT   21 33 52.6   +55 47 18    11.268   10.936   68.3    4.9   277   28.1 
2024-04-29 00:00 UT   21 34 05.3   +55 51 41    11.270   10.942   68.5    4.9   276   28.1 
2024-04-30 00:00 UT   21 34 17.5   +55 56 04    11.272   10.949   68.8    4.9   275   28.1 
2024-05-01 00:00 UT   21 34 29.0   +56 00 28    11.275   10.955   69.1    4.9   274   28.1 
2024-05-02 00:00 UT   21 34 40.1   +56 04 51    11.277   10.962   69.3    4.9   273   28.1 
2024-05-03 00:00 UT   21 34 50.6   +56 09 15    11.279   10.968   69.6    4.9   272   28.1 
2024-05-04 00:00 UT   21 35 00.5   +56 13 39    11.280   10.975   69.9    4.9   271   28.1 
2024-05-05 00:00 UT   21 35 09.9   +56 18 03    11.282   10.981   70.1    5.0   270   28.1 

    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.