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	00h20m	-69°05'	60.5°	25.1°	132°
Nearest approach	22 Feb 2020	14.1	2.028 AU	2.297 AU	01h28m	-62°10'	61.9°	25.5°	125°
Today	22 Oct 2025	27.3	16.144 AU	15.681 AU	04h42m	+68°45'	116.1°	3.2°	229°

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)                : 0.9992430
    q (Perihelion distance)         : 2.0230240
    i (Inclination)                 : 87.02440
    Ω (Longitude of ascending node) : 73.31750
    ω (Argument of perihelion)      : 265.79380
    L (Longitude of perihelion)     : 108.53359
    B (Latitude of perihelion)      : -84.84923
    T (Time of perihelion passage)  : 2458889.98800
    P (Orbital period in years)     : 138152.18

    Epoch                           : 2025 Oct 21
    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
2025-10-21 00:00 UT   04 43 33.1   +68 41 40    15.688   16.134  115.0    3.2   230   27.3 
2025-10-22 00:00 UT   04 43 02.1   +68 43 44    15.684   16.139  115.6    3.2   229   27.3 
2025-10-22 20:55 UT   04 42 34.6   +68 45 29    15.681   16.144  116.1    3.2   229   27.3 
2025-10-23 00:00 UT   04 42 30.5   +68 45 45    15.681   16.145  116.2    3.2   228   27.3 
2025-10-24 00:00 UT   04 41 58.3   +68 47 43    15.677   16.151  116.8    3.2   227   27.3 
2025-10-25 00:00 UT   04 41 25.5   +68 49 39    15.674   16.156  117.4    3.1   226   27.3 
2025-10-26 00:00 UT   04 40 52.1   +68 51 32    15.671   16.162  118.0    3.1   225   27.3 
2025-10-27 00:00 UT   04 40 18.2   +68 53 22    15.668   16.168  118.6    3.1   224   27.3 
2025-10-28 00:00 UT   04 39 43.7   +68 55 09    15.665   16.173  119.2    3.1   223   27.3 
2025-10-29 00:00 UT   04 39 08.7   +68 56 54    15.663   16.179  119.7    3.1   222   27.3 
2025-10-30 00:00 UT   04 38 33.1   +68 58 35    15.660   16.184  120.3    3.0   221   27.3 
2025-10-31 00:00 UT   04 37 57.0   +69 00 13    15.658   16.190  120.9    3.0   220   27.3 
2025-11-01 00:00 UT   04 37 20.5   +69 01 48    15.656   16.196  121.4    3.0   218   27.3 

    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.