C/2020 K8 (Catalina-ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	15 Aug 2020	14.9	0.871 AU	0.573 AU	05h31m	+27°00'	59.2°	86.4°	269°
Perihelion	15 Sep 2020	15.5	0.473 AU	1.090 AU	09h53m	-00°49'	25.7°	67.2°	262°
Today	2 Aug 2026	26.1	17.871 AU	17.599 AU	15h57m	+07°49'	103.9°	3.2°	111°

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 16.2 + 5 log[∆] + 2.9 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/2020 K8 (Catalina-ATLAS) are:

    e (Eccentricity)                : 1.0003650
    q (Perihelion distance)         : 0.4731330
    i (Inclination)                 : 31.29930
    Ω (Longitude of ascending node) : 181.12570
    ω (Argument of perihelion)      : 260.35640
    L (Longitude of perihelion)     : 259.87851
    B (Latitude of perihelion)      : -30.80831
    T (Time of perihelion passage)  : 2459108.38430

    Epoch                           : 2026 May 29
    Reference                       : MPC194168

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-08-01 00:00 UT   15 57 27.5   +07 50 40    17.576   17.864  104.9    3.1   111   26.1 
2026-08-02 00:00 UT   15 57 23.6   +07 49 26    17.596   17.870  104.0    3.2   111   26.1 
2026-08-02 03:12 UT   15 57 23.1   +07 49 16    17.599   17.871  103.9    3.2   111   26.1 
2026-08-03 00:00 UT   15 57 19.8   +07 48 11    17.616   17.876  103.2    3.2   110   26.1 
2026-08-04 00:00 UT   15 57 16.3   +07 46 55    17.637   17.881  102.3    3.2   110   26.1 
2026-08-05 00:00 UT   15 57 12.9   +07 45 38    17.657   17.887  101.5    3.2   109   26.1 
2026-08-06 00:00 UT   15 57 09.8   +07 44 19    17.677   17.893  100.6    3.2   109   26.1 
2026-08-07 00:00 UT   15 57 06.9   +07 43 01    17.698   17.898   99.8    3.2   108   26.1 
2026-08-08 00:00 UT   15 57 04.2   +07 41 41    17.718   17.904   98.9    3.2   108   26.1 
2026-08-09 00:00 UT   15 57 01.8   +07 40 20    17.739   17.910   98.1    3.2   107   26.1 
2026-08-10 00:00 UT   15 56 59.5   +07 38 58    17.759   17.915   97.2    3.2   107   26.1 
2026-08-11 00:00 UT   15 56 57.5   +07 37 36    17.780   17.921   96.4    3.2   107   26.1 
2026-08-12 00:00 UT   15 56 55.7   +07 36 13    17.800   17.927   95.5    3.2   106   26.1 

    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.