C/2024 J3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	18 Jul 2026	14.3	4.027 AU	3.450 AU	19h30m	+40°53'	117.9°	12.9°	175°
Nearest approach	25 Jul 2026	14.3	4.011 AU	3.445 AU	19h21m	+41°51'	117.1°	13.0°	165°
Perihelion	25 Nov 2026	14.4	3.865 AU	4.025 AU	18h55m	+41°11'	73.7°	14.2°	42°

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 5.5 + 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/2024 J3 (ATLAS) are:

    e (Eccentricity)                : 1.0000430
    q (Perihelion distance)         : 3.8654960
    i (Inclination)                 : 75.63950
    Ω (Longitude of ascending node) : 285.96000
    ω (Argument of perihelion)      : 74.09020
    L (Longitude of perihelion)     : 326.98729
    B (Latitude of perihelion)      : 68.69282
    T (Time of perihelion passage)  : 2461369.92250

    Epoch                           : 2026 Jul 18
    Reference                       : MPEC 2026-O09

    Classification(s):              : Nearly isotropic; New (a > 10000 AU)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-07-17 00:00 UT   19 32 41.0   +40 36 27     3.453    4.032  118.0   12.9   177   14.3 
2026-07-18 00:00 UT   19 31 21.2   +40 46 18     3.451    4.029  118.0   12.9   176   14.3 
2026-07-18 18:36 UT   19 30 19.2   +40 53 44     3.450    4.027  117.9   12.9   175   14.3 
2026-07-19 00:00 UT   19 30 01.1   +40 55 51     3.450    4.027  117.9   12.9   174   14.3 
2026-07-20 00:00 UT   19 28 40.7   +41 05 06     3.449    4.024  117.8   12.9   173   14.3 
2026-07-21 00:00 UT   19 27 20.0   +41 14 04     3.447    4.022  117.7   12.9   171   14.3 
2026-07-22 00:00 UT   19 25 59.1   +41 22 43     3.447    4.020  117.6   12.9   170   14.3 
2026-07-23 00:00 UT   19 24 38.1   +41 31 04     3.446    4.017  117.5   13.0   169   14.3 
2026-07-24 00:00 UT   19 23 17.0   +41 39 08     3.446    4.015  117.3   13.0   167   14.3 
2026-07-25 00:00 UT   19 21 55.8   +41 46 53     3.445    4.013  117.2   13.0   166   14.3 
2026-07-26 00:00 UT   19 20 34.7   +41 54 20     3.445    4.010  117.0   13.0   164   14.3 
2026-07-27 00:00 UT   19 19 13.6   +42 01 29     3.446    4.008  116.8   13.1   163   14.3 
2026-07-28 00:00 UT   19 17 52.6   +42 08 21     3.446    4.006  116.7   13.1   161   14.3 

    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.