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	6.566 AU	5.988 AU	10h40m	-18°46'	121.2°	7.6°	98°
Today	26 Jan 2026	23.0	14.252 AU	14.875 AU	17h36m	+03°45'	49.2°	3.0°	299°

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)                : 0.9907320
    q (Perihelion distance)         : 6.5664940
    i (Inclination)                 : 36.03190
    Ω (Longitude of ascending node) : 212.35630
    ω (Argument of perihelion)      : 319.02860
    L (Longitude of perihelion)     : 177.27690
    B (Latitude of perihelion)      : -22.68693
    T (Time of perihelion passage)  : 2458974.38830
    P (Orbital period in years)     : 18859.11

    Epoch                           : 2025 Nov 12
    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
2026-01-25 00:00 UT   17 35 40.8   +03 43 28    14.883   14.245   48.1    2.9   300   23.0 
2026-01-26 00:00 UT   17 35 56.7   +03 44 54    14.878   14.250   48.9    3.0   299   23.0 
2026-01-26 10:06 UT   17 36 03.4   +03 45 31    14.875   14.252   49.2    3.0   299   23.0 
2026-01-27 00:00 UT   17 36 12.5   +03 46 21    14.872   14.255   49.6    3.0   298   23.0 
2026-01-28 00:00 UT   17 36 28.0   +03 47 51    14.866   14.259   50.4    3.1   298   23.0 
2026-01-29 00:00 UT   17 36 43.4   +03 49 21    14.860   14.264   51.2    3.1   297   23.0 
2026-01-30 00:00 UT   17 36 58.7   +03 50 54    14.854   14.269   52.0    3.1   296   23.0 
2026-01-31 00:00 UT   17 37 13.7   +03 52 28    14.848   14.274   52.8    3.2   296   23.0 
2026-02-01 00:00 UT   17 37 28.5   +03 54 03    14.841   14.278   53.6    3.2   295   23.0 
2026-02-02 00:00 UT   17 37 43.2   +03 55 40    14.835   14.283   54.3    3.2   294   23.0 
2026-02-03 00:00 UT   17 37 57.6   +03 57 18    14.828   14.288   55.1    3.2   294   23.0 
2026-02-04 00:00 UT   17 38 11.9   +03 58 58    14.821   14.292   55.9    3.3   293   23.0 
2026-02-05 00:00 UT   17 38 26.0   +04 00 39    14.814   14.297   56.7    3.3   292   23.0 

    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.