C/2019 K1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	10 Feb 2020	14.2	2.023 AU	2.317 AU	00h19m	-69°07'	60.5°	25.1°	132°
Nearest approach	22 Feb 2020	14.1	2.028 AU	2.297 AU	01h28m	-62°11'	61.9°	25.5°	125°
Today	6 Dec 2025	27.4	16.393 AU	15.707 AU	04h12m	+69°21'	132.8°	2.5°	168°

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 9.3 + 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 K1 (ATLAS) are:

    e (Eccentricity)                : 0.9992320
    q (Perihelion distance)         : 2.0232880
    i (Inclination)                 : 87.02640
    Ω (Longitude of ascending node) : 73.31950
    ω (Argument of perihelion)      : 265.79570
    L (Longitude of perihelion)     : 108.52970
    B (Latitude of perihelion)      : -84.85194
    T (Time of perihelion passage)  : 2458889.92050
    P (Orbital period in years)     : 135221.18

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2022-O08

    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
2025-12-05 00:00 UT   04 13 38.6   +69 21 37    15.702   16.387  132.7    2.5   170   27.4 
2025-12-06 00:00 UT   04 12 55.6   +69 21 09    15.707   16.393  132.8    2.5   168   27.4 
2025-12-06 01:12 UT   04 12 53.4   +69 21 08    15.707   16.393  132.8    2.5   168   27.4 
2025-12-07 00:00 UT   04 12 12.7   +69 20 37    15.713   16.398  132.8    2.5   167   27.4 
2025-12-08 00:00 UT   04 11 30.0   +69 20 02    15.718   16.404  132.8    2.5   165   27.4 
2025-12-09 00:00 UT   04 10 47.6   +69 19 24    15.724   16.410  132.8    2.5   164   27.4 
2025-12-10 00:00 UT   04 10 05.3   +69 18 42    15.730   16.415  132.8    2.5   162   27.4 
2025-12-11 00:00 UT   04 09 23.3   +69 17 56    15.736   16.421  132.7    2.5   160   27.4 
2025-12-12 00:00 UT   04 08 41.6   +69 17 08    15.743   16.426  132.7    2.5   159   27.4 
2025-12-13 00:00 UT   04 08 00.1   +69 16 16    15.749   16.432  132.6    2.5   157   27.4 
2025-12-14 00:00 UT   04 07 19.0   +69 15 20    15.756   16.438  132.5    2.5   156   27.4 
2025-12-15 00:00 UT   04 06 38.2   +69 14 22    15.763   16.443  132.4    2.5   154   27.4 
2025-12-16 00:00 UT   04 05 57.7   +69 13 20    15.771   16.449  132.2    2.5   152   27.4 

    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.