C/2021 K1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	3 May 2021	16.1	2.501 AU	2.889 AU	23h06m	-06°53'	57.8°	19.9°	247°
Nearest approach	12 Sep 2021	15.6	2.808 AU	1.883 AU	01h15m	-10°38'	151.3°	9.9°	281°
Today	31 Oct 2024	24.3	9.441 AU	8.984 AU	06h50m	+10°51'	114.6°	5.5°	281°

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.)

The orbital elements of C/2021 K1 (ATLAS) are:

            e (Eccentricity)                : 0.8019190
            q (Perihelion distance)         : 2.5012770
            i (Inclination)                 : 16.27260
            Ω (Longitude of ascending node) : 140.91890
            ω (Argument of perihelion)      : 184.25190
            L (Longitude of perihelion)     : 145.00105
            B (Latitude of perihelion)      : -1.19041
            T (Time of perihelion passage)  : 2459337.68840
            P (Orbital period in years)     : 44.87

            Epoch                           : 2024 Oct 29
            Reference                       : MPEC 2022-O08

            Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); Halley type (P < 200 years)
        

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (11.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 9.79 + 5 log[∆] + 10.00 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2024-10-31 00:00 UT   06 50 07.3   +10 51 38     8.985    9.441  114.5    5.5   281   24.3 
2024-10-31 01:08 UT   06 50 06.9   +10 51 36     8.984    9.441  114.6    5.5   281   24.3 
2024-11-01 00:00 UT   06 50 00.0   +10 50 53     8.975    9.446  115.5    5.4   281   24.3 
2024-11-02 00:00 UT   06 49 52.4   +10 50 10     8.965    9.451  116.5    5.4   281   24.3 
2024-11-03 00:00 UT   06 49 44.3   +10 49 28     8.955    9.455  117.5    5.3   281   24.3 
2024-11-04 00:00 UT   06 49 35.8   +10 48 47     8.946    9.460  118.6    5.3   282   24.3 
2024-11-05 00:00 UT   06 49 26.8   +10 48 07     8.937    9.465  119.6    5.2   282   24.3 
2024-11-06 00:00 UT   06 49 17.5   +10 47 28     8.927    9.470  120.6    5.2   282   24.3 
2024-11-07 00:00 UT   06 49 07.7   +10 46 51     8.918    9.475  121.6    5.1   283   24.3 
2024-11-08 00:00 UT   06 48 57.5   +10 46 14     8.909    9.480  122.6    5.1   283   24.3 
2024-11-09 00:00 UT   06 48 46.9   +10 45 39     8.901    9.485  123.6    5.0   283   24.3 
2024-11-10 00:00 UT   06 48 35.9   +10 45 05     8.892    9.490  124.6    4.9   283   24.3 

    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.