C/2019 M3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	16 Dec 2018	13.8	2.430 AU	2.432 AU	17h24m	+54°52'	78.2°	23.4°	357°
Perihelion	31 Dec 2018	13.8	2.424 AU	2.467 AU	18h39m	+52°52'	76.0°	23.2°	359°
Today	15 Oct 2025	26.8	18.038 AU	17.665 AU	23h12m	-55°40'	110.4°	3.0°	34°

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 8.0 + 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 M3 (ATLAS) are:

    e (Eccentricity)                : 0.9995380
    q (Perihelion distance)         : 2.4241890
    i (Inclination)                 : 99.67090
    Ω (Longitude of ascending node) : 155.07080
    ω (Argument of perihelion)      : 87.93520
    L (Longitude of perihelion)     : 77.18368
    B (Latitude of perihelion)      : 80.11318
    T (Time of perihelion passage)  : 2458484.07910
    P (Orbital period in years)     : 380090.27

    Epoch                           : 2025 Oct 14
    Reference                       : MPC118095

    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
2025-10-15 00:00 UT   23 12 20.6   -55 40 14    17.659   18.036  110.7    3.0    34   26.8 
2025-10-15 09:44 UT   23 12 13.8   -55 40 02    17.665   18.038  110.4    3.0    34   26.8 
2025-10-16 00:00 UT   23 12 03.9   -55 39 44    17.675   18.041  110.0    3.0    35   26.8 
2025-10-17 00:00 UT   23 11 47.5   -55 39 11    17.691   18.047  109.4    3.0    36   26.8 
2025-10-18 00:00 UT   23 11 31.4   -55 38 35    17.707   18.052  108.7    3.0    36   26.8 
2025-10-19 00:00 UT   23 11 15.5   -55 37 57    17.724   18.057  108.0    3.0    37   26.8 
2025-10-20 00:00 UT   23 10 59.9   -55 37 15    17.740   18.063  107.4    3.0    38   26.8 
2025-10-21 00:00 UT   23 10 44.5   -55 36 32    17.757   18.068  106.7    3.0    39   26.8 
2025-10-22 00:00 UT   23 10 29.5   -55 35 45    17.773   18.073  106.0    3.0    40   26.8 
2025-10-23 00:00 UT   23 10 14.7   -55 34 56    17.790   18.079  105.3    3.0    41   26.8 
2025-10-24 00:00 UT   23 10 00.3   -55 34 05    17.807   18.084  104.6    3.1    41   26.8 
2025-10-25 00:00 UT   23 09 46.1   -55 33 10    17.824   18.089  103.9    3.1    42   26.8 

    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.