C/2019 T3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	4 Mar 2021	16.6	5.953 AU	6.552 AU	22h50m	+43°00'	49.3°	7.3°	356°
Nearest approach	11 Sep 2021	16.3	6.102 AU	5.375 AU	22h03m	+39°31'	132.7°	7.0°	155°
Today	1 Jul 2025	20.8	11.840 AU	11.000 AU	21h16m	-37°04'	144.2°	2.9°	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/2019 T3 (ATLAS) are:

            e (Eccentricity)                : 0.9987020
            q (Perihelion distance)         : 5.9534930
            i (Inclination)                 : 121.87430
            Ω (Longitude of ascending node) : 139.54340
            ω (Argument of perihelion)      : 112.48840
            L (Longitude of perihelion)     : 191.44834
            B (Latitude of perihelion)      : 51.68668
            T (Time of perihelion passage)  : 2459278.22030
            P (Orbital period in years)     : 310631.67

            Epoch                           : 2025 Jun 30
            Reference                       : MPEC 2023-UR6

            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 (6.80 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 4.81 + 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
2025-07-01 00:00 UT   21 16 44.3   -37 01 25    11.002   11.836  143.6    2.9   281   20.8 
2025-07-01 18:31 UT   21 16 27.0   -37 04 22    11.000   11.840  144.2    2.9   282   20.8 
2025-07-02 00:00 UT   21 16 21.8   -37 05 15    10.999   11.841  144.4    2.9   282   20.8 
2025-07-03 00:00 UT   21 15 59.0   -37 09 05    10.996   11.846  145.2    2.8   283   20.8 
2025-07-04 00:00 UT   21 15 36.0   -37 12 53    10.994   11.851  146.0    2.7   285   20.8 
2025-07-05 00:00 UT   21 15 12.6   -37 16 41    10.991   11.856  146.8    2.7   286   20.8 
2025-07-06 00:00 UT   21 14 48.9   -37 20 28    10.989   11.861  147.6    2.6   287   20.8 
2025-07-07 00:00 UT   21 14 25.0   -37 24 13    10.988   11.866  148.4    2.6   289   20.8 
2025-07-08 00:00 UT   21 14 00.8   -37 27 58    10.986   11.871  149.2    2.5   290   20.8 
2025-07-09 00:00 UT   21 13 36.4   -37 31 41    10.985   11.876  149.9    2.5   292   20.8 
2025-07-10 00:00 UT   21 13 11.7   -37 35 23    10.984   11.881  150.6    2.4   293   20.8 
2025-07-11 00:00 UT   21 12 46.7   -37 39 04    10.983   11.886  151.3    2.4   295   20.8 

    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.