C/2021 K3 (Catalina)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	3 Feb 2022	21.1	5.228 AU	6.156 AU	19h55m	-22°02'	18.0°	3.3°	255°
Nearest approach	28 Jun 2022	20.5	5.340 AU	4.360 AU	19h01m	-38°55'	162.8°	3.2°	333°
Today	22 Jun 2025	25.0	10.071 AU	9.827 AU	11h23m	-48°23'	101.0°	5.7°	113°

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 K3 (Catalina) are:

            e (Eccentricity)                : 1.0041980
            q (Perihelion distance)         : 5.2276870
            i (Inclination)                 : 134.78050
            Ω (Longitude of ascending node) : 114.60790
            ω (Argument of perihelion)      : 182.01380
            L (Longitude of perihelion)     : 113.18910
            B (Latitude of perihelion)      : -1.42927
            T (Time of perihelion passage)  : 2459614.14950

            Epoch                           : 2025 Jun 21
            Reference                       : MPEC 2022-L66

            Classification(s):              : Nearly isotropic; New (a > 10000 AU)
        

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 light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (10.00 + 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
2025-06-22 00:00 UT   11 23 56.6   -48 26 08     9.819   10.068  101.3    5.7   113   25.0 
2025-06-22 11:43 UT   11 23 55.6   -48 23 25     9.827   10.071  101.0    5.7   113   25.0 
2025-06-23 00:00 UT   11 23 54.8   -48 20 36     9.836   10.074  100.7    5.7   113   25.0 
2025-06-24 00:00 UT   11 23 53.5   -48 15 09     9.853   10.079  100.0    5.7   114   25.0 
2025-06-25 00:00 UT   11 23 52.9   -48 09 45     9.870   10.084   99.3    5.7   115   25.0 
2025-06-26 00:00 UT   11 23 52.7   -48 04 24     9.887   10.090   98.6    5.7   116   25.0 
2025-06-27 00:00 UT   11 23 53.1   -47 59 07     9.904   10.095   97.9    5.7   116   25.0 
2025-06-28 00:00 UT   11 23 54.0   -47 53 54     9.922   10.100   97.2    5.7   117   25.0 
2025-06-29 00:00 UT   11 23 55.5   -47 48 45     9.939   10.106   96.5    5.7   118   25.0 
2025-06-30 00:00 UT   11 23 57.4   -47 43 39     9.956   10.111   95.8    5.7   118   25.0 
2025-07-01 00:00 UT   11 23 59.8   -47 38 38     9.974   10.116   95.1    5.7   119   25.0 
2025-07-02 00:00 UT   11 24 02.8   -47 33 40     9.991   10.122   94.5    5.7   120   25.1 

    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.