C/2017 K4 (ATLAS)
ephemeris date magn radius delta ra dec elong phase PA
Nearest approach3 Jul 201716.83.244 AU2.316 AU16h52m-36°18'151.2°8.7°71°
Perihelion7 Jan 201816.92.664 AU3.570 AU20h32m-15°28'19.6°7.1°67°
Today28 Mar 202427.715.374 AU15.493 AU05h55m+30°52'81.3°3.7°88°
C/2017 K4 (ATLAS)- 2024-03-28
astro.vanbuitenen.nl


 
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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/2017 K4 (ATLAS) are:

            e (Eccentricity)                : 0.9072110
            q (Perihelion distance)         : 2.6635700
            i (Inclination)                 : 16.65690
            Ω (Longitude of ascending node) : 298.92790
            ω (Argument of perihelion)      : 15.35860
            L (Longitude of perihelion)     : 313.67067
            B (Latitude of perihelion)      : 4.35404
            T (Time of perihelion passage)  : 2458126.44910
            P (Orbital period in years)     : 153.80

            Epoch                           : 2023 Jan 31
            Reference                       : MPC114598

            Classification(s):              : Ecliptic; Jupiter family
            Tisserand (Jupiter)             : 2.075
        

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 (10.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 9.84 + 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
2024-03-28 00:00 UT   05 55 55.1   +30 52 45    15.484   15.373   81.7    3.7    88   27.7 
2024-03-28 10:02 UT   05 55 57.3   +30 52 29    15.493   15.374   81.3    3.7    88   27.7 
2024-03-29 00:00 UT   05 56 00.4   +30 52 08    15.506   15.377   80.8    3.7    88   27.7 
2024-03-30 00:00 UT   05 56 05.9   +30 51 31    15.527   15.382   79.8    3.7    88   27.7 
2024-03-31 00:00 UT   05 56 11.8   +30 50 54    15.548   15.387   78.8    3.7    88   27.7 
2024-04-01 00:00 UT   05 56 17.9   +30 50 17    15.570   15.391   77.9    3.6    88   27.7 
2024-04-02 00:00 UT   05 56 24.4   +30 49 41    15.591   15.396   76.9    3.6    88   27.7 
2024-04-03 00:00 UT   05 56 31.1   +30 49 05    15.612   15.401   76.0    3.6    88   27.7 
2024-04-04 00:00 UT   05 56 38.0   +30 48 29    15.633   15.405   75.0    3.6    88   27.7 
2024-04-05 00:00 UT   05 56 45.3   +30 47 53    15.654   15.410   74.1    3.6    88   27.7 
2024-04-06 00:00 UT   05 56 52.8   +30 47 17    15.675   15.415   73.1    3.6    87   27.7 
2024-04-07 00:00 UT   05 57 00.6   +30 46 42    15.696   15.419   72.2    3.5    87   27.7 


    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.