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	19 Jul 2026	26.0	17.791 AU	17.326 AU	15h58m	+08°04'	115.7°	3.0°	118°

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
2026-07-18 00:00 UT   15 58 45.1   +08 06 03    17.305   17.784  116.6    2.9   119   26.0 
2026-07-19 00:00 UT   15 58 38.2   +08 05 05    17.324   17.790  115.8    2.9   118   26.0 
2026-07-19 03:09 UT   15 58 37.4   +08 04 58    17.326   17.791  115.7    3.0   118   26.0 
2026-07-20 00:00 UT   15 58 31.6   +08 04 06    17.342   17.796  115.0    3.0   117   26.0 
2026-07-21 00:00 UT   15 58 25.1   +08 03 05    17.361   17.801  114.1    3.0   117   26.0 
2026-07-22 00:00 UT   15 58 18.8   +08 02 04    17.380   17.807  113.3    3.0   116   26.0 
2026-07-23 00:00 UT   15 58 12.8   +08 01 00    17.400   17.813  112.4    3.0   116   26.0 
2026-07-24 00:00 UT   15 58 06.9   +07 59 56    17.419   17.819  111.6    3.0   115   26.0 
2026-07-25 00:00 UT   15 58 01.3   +07 58 51    17.438   17.824  110.8    3.1   115   26.0 
2026-07-26 00:00 UT   15 57 55.8   +07 57 44    17.458   17.830  109.9    3.1   114   26.0 
2026-07-27 00:00 UT   15 57 50.6   +07 56 36    17.477   17.836  109.1    3.1   114   26.0 
2026-07-28 00:00 UT   15 57 45.6   +07 55 27    17.497   17.841  108.2    3.1   113   26.1 
2026-07-29 00:00 UT   15 57 40.7   +07 54 17    17.517   17.847  107.4    3.1   113   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.