C/2018 N1 (NEOWISE)
ephemeris date magn radius delta ra dec elong phase PA
Nearest approach27 Jul 20189.01.310 AU0.306 AU20h24m-37°13'161.9°13.9°2°
Perihelion3 Aug 20189.51.306 AU0.397 AU17h20m-29°14'130.2°36.4°89°
Today15 Jun 202529.619.012 AU19.508 AU09h59m+24°27'59.5°2.6°104°
C/2018 N1 (NEOWISE)- 2025-06-15
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/2018 N1 (NEOWISE) are:

            e (Eccentricity)                : 0.9974900
            q (Perihelion distance)         : 1.3062340
            i (Inclination)                 : 159.38870
            Ω (Longitude of ascending node) : 292.59000
            ω (Argument of perihelion)      : 354.74820
            L (Longitude of perihelion)     : 297.50734
            B (Latitude of perihelion)      : -1.84650
            T (Time of perihelion passage)  : 2458333.93300
            P (Orbital period in years)     : 11871.92

            Epoch                           : 2023 Sep 24
            Reference                       : MPEC 2022-M21

            Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)
        

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 (15.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 10.36 + 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
2025-06-15 00:00 UT   09 59 48.3   +24 28 21    19.488   19.007   60.4    2.7   104   29.6 
2025-06-15 23:48 UT   09 59 52.7   +24 27 22    19.508   19.012   59.5    2.6   104   29.6 
2025-06-16 00:00 UT   09 59 52.8   +24 27 21    19.508   19.012   59.4    2.6   104   29.6 
2025-06-17 00:00 UT   09 59 57.4   +24 26 20    19.527   19.018   58.5    2.6   103   29.6 
2025-06-18 00:00 UT   10 00 02.3   +24 25 19    19.547   19.023   57.6    2.6   103   29.6 
2025-06-19 00:00 UT   10 00 07.3   +24 24 17    19.566   19.028   56.7    2.6   103   29.6 
2025-06-20 00:00 UT   10 00 12.5   +24 23 14    19.585   19.034   55.8    2.5   103   29.6 
2025-06-21 00:00 UT   10 00 17.8   +24 22 12    19.604   19.039   54.9    2.5   102   29.6 
2025-06-22 00:00 UT   10 00 23.3   +24 21 08    19.623   19.044   54.0    2.5   102   29.6 
2025-06-23 00:00 UT   10 00 29.0   +24 20 05    19.642   19.050   53.1    2.4   102   29.6 
2025-06-24 00:00 UT   10 00 34.8   +24 19 01    19.660   19.055   52.2    2.4   102   29.6 
2025-06-25 00:00 UT   10 00 40.8   +24 17 56    19.678   19.060   51.3    2.4   101   29.6 

































































    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.