C/2019 J3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	24 Jun 2019	18.0	2.397 AU	1.384 AU	17h48m	-20°46'	174.5°	2.3°	120°
Perihelion	1 Aug 2019	18.6	2.360 AU	1.871 AU	15h44m	-03°49'	105.8°	24.5°	108°
Today	21 Jul 2026	32.6	18.439 AU	19.389 AU	07h33m	+39°49'	20.2°	1.1°	341°

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. (13.5 + 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/2019 J3 (ATLAS) are:

    e (Eccentricity)                : 0.9996060
    q (Perihelion distance)         : 2.3595990
    i (Inclination)                 : 131.30490
    Ω (Longitude of ascending node) : 270.64860
    ω (Argument of perihelion)      : 16.43730
    L (Longitude of perihelion)     : 259.62902
    B (Latitude of perihelion)      : 12.27278
    T (Time of perihelion passage)  : 2458696.50450
    P (Orbital period in years)     : 463460.76

    Epoch                           : 2026 May 29
    Reference                       : MPC194161

    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
2026-07-20 00:00 UT   07 33 03.0   +39 49 60    19.386   18.433   19.7    1.1   344   32.6 
2026-07-21 00:00 UT   07 33 16.8   +39 49 27    19.388   18.438   20.1    1.1   342   32.6 
2026-07-21 05:16 UT   07 33 19.8   +39 49 20    19.389   18.439   20.2    1.1   341   32.6 
2026-07-22 00:00 UT   07 33 30.6   +39 48 56    19.391   18.443   20.5    1.1   339   32.6 
2026-07-23 00:00 UT   07 33 44.3   +39 48 25    19.393   18.449   20.9    1.1   337   32.6 
2026-07-24 00:00 UT   07 33 58.0   +39 47 55    19.395   18.454   21.4    1.2   335   32.6 
2026-07-25 00:00 UT   07 34 11.6   +39 47 26    19.397   18.459   21.9    1.2   333   32.6 
2026-07-26 00:00 UT   07 34 25.2   +39 46 58    19.398   18.464   22.5    1.2   331   32.6 
2026-07-27 00:00 UT   07 34 38.8   +39 46 31    19.400   18.470   23.0    1.2   329   32.6 
2026-07-28 00:00 UT   07 34 52.2   +39 46 05    19.401   18.475   23.6    1.3   327   32.6 
2026-07-29 00:00 UT   07 35 05.6   +39 45 40    19.401   18.480   24.2    1.3   326   32.6 
2026-07-30 00:00 UT   07 35 19.0   +39 45 16    19.402   18.486   24.8    1.3   324   32.6 
2026-07-31 00:00 UT   07 35 32.3   +39 44 53    19.402   18.491   25.4    1.4   323   32.6 

    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.