C/2018 F3 (Johnson)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Aug 2017	19.2	2.483 AU	2.872 AU	10h06m	-43°17'	57.7°	20.2°	172°
Nearest approach	3 Mar 2018	20.0	3.269 AU	2.326 AU	11h44m	-10°36'	158.5°	6.4°	324°
Today	24 Apr 2024	31.8	17.812 AU	17.735 AU	12h50m	+73°30'	92.7°	3.2°	161°

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/2018 F3 (Johnson) are:

            e (Eccentricity)                : 1.0000000
            q (Perihelion distance)         : 2.4831720
            i (Inclination)                 : 105.53480
            Ω (Longitude of ascending node) : 173.03110
            ω (Argument of perihelion)      : 293.01130
            L (Longitude of perihelion)     : 205.26692
            B (Latitude of perihelion)      : -62.47418
            T (Time of perihelion passage)  : 2457980.73130

            Epoch                           : 
            Reference                       : MPC110084

            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. (13.00 + 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
2024-04-24 00:00 UT   12 50 23.9   +73 30 14    17.733   17.811   92.8    3.2   161   31.8 
2024-04-24 02:11 UT   12 50 20.5   +73 30 11    17.735   17.812   92.7    3.2   161   31.8 
2024-04-25 00:00 UT   12 49 45.9   +73 29 42    17.746   17.816   92.4    3.2   160   31.8 
2024-04-26 00:00 UT   12 49 08.2   +73 29 06    17.759   17.822   91.9    3.2   159   31.8 
2024-04-27 00:00 UT   12 48 30.8   +73 28 26    17.772   17.827   91.5    3.2   158   31.8 
2024-04-28 00:00 UT   12 47 53.9   +73 27 43    17.784   17.833   91.1    3.2   157   31.8 
2024-04-29 00:00 UT   12 47 17.4   +73 26 57    17.797   17.838   90.7    3.2   156   31.8 
2024-04-30 00:00 UT   12 46 41.3   +73 26 07    17.810   17.843   90.2    3.2   155   31.8 
2024-05-01 00:00 UT   12 46 05.6   +73 25 13    17.823   17.849   89.8    3.2   154   31.8 
2024-05-02 00:00 UT   12 45 30.4   +73 24 17    17.835   17.854   89.4    3.2   153   31.8 
2024-05-03 00:00 UT   12 44 55.7   +73 23 17    17.848   17.859   89.0    3.2   152   31.8 
2024-05-04 00:00 UT   12 44 21.5   +73 22 14    17.861   17.865   88.6    3.2   151   31.8 

    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.