C/2019 C1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	16 Mar 2020	17.6	6.575 AU	5.687 AU	10h45m	-23°25'	151.0°	4.2°	33°
Perihelion	4 May 2020	17.7	6.567 AU	5.987 AU	10h40m	-18°47'	121.2°	7.5°	98°
Today	26 Oct 2025	22.8	13.821 AU	14.462 AU	17h07m	+03°34'	48.3°	3.1°	70°

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 5.6 + 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 C1 (ATLAS) are:

    e (Eccentricity)                : 0.9906980
    q (Perihelion distance)         : 6.5665120
    i (Inclination)                 : 36.03260
    Ω (Longitude of ascending node) : 212.35800
    ω (Argument of perihelion)      : 319.02640
    L (Longitude of perihelion)     : 177.27675
    B (Latitude of perihelion)      : -22.68839
    T (Time of perihelion passage)  : 2458974.34600
    P (Orbital period in years)     : 18755.89

    Epoch                           : 2025 Oct 26
    Reference                       : MPEC 2021-P47

    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
2025-10-25 00:00 UT   17 07 09.9   +03 36 54    14.435   13.813   49.7    3.1    71   22.8 
2025-10-26 00:00 UT   17 07 25.8   +03 35 44    14.450   13.817   48.9    3.1    70   22.8 
2025-10-26 19:37 UT   17 07 38.9   +03 34 49    14.462   13.821   48.3    3.1    70   22.8 
2025-10-27 00:00 UT   17 07 41.9   +03 34 36    14.464   13.822   48.2    3.1    69   22.8 
2025-10-28 00:00 UT   17 07 58.1   +03 33 30    14.479   13.827   47.5    3.0    69   22.8 
2025-10-29 00:00 UT   17 08 14.5   +03 32 24    14.493   13.832   46.7    3.0    68   22.8 
2025-10-30 00:00 UT   17 08 31.0   +03 31 20    14.508   13.836   46.0    3.0    67   22.8 
2025-10-31 00:00 UT   17 08 47.7   +03 30 17    14.522   13.841   45.3    2.9    66   22.8 
2025-11-01 00:00 UT   17 09 04.6   +03 29 15    14.535   13.846   44.5    2.9    65   22.8 
2025-11-02 00:00 UT   17 09 21.6   +03 28 15    14.549   13.850   43.8    2.8    65   22.8 
2025-11-03 00:00 UT   17 09 38.7   +03 27 16    14.562   13.855   43.1    2.8    64   22.8 
2025-11-04 00:00 UT   17 09 56.0   +03 26 19    14.576   13.860   42.4    2.8    63   22.8 
2025-11-05 00:00 UT   17 10 13.4   +03 25 22    14.589   13.865   41.7    2.7    62   22.8 

    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.