C/2019 H1 (NEOWISE)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	26 Apr 2019	18.8	1.839 AU	1.440 AU	19h46m	+03°17'	95.9°	33.0°	256°
Nearest approach	22 May 2019	18.6	1.867 AU	1.223 AU	18h50m	+31°39'	113.0°	29.9°	225°
Today	18 Sep 2025	34.1	17.548 AU	17.714 AU	06h36m	+40°19'	78.9°	3.2°	277°

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/2019 H1 (NEOWISE) are:

            e (Eccentricity)                : 0.9918470
            q (Perihelion distance)         : 1.8393770
            i (Inclination)                 : 104.35500
            Ω (Longitude of ascending node) : 269.31280
            ω (Argument of perihelion)      : 19.22890
            L (Longitude of perihelion)     : 264.37026
            B (Latitude of perihelion)      : 18.60610
            T (Time of perihelion passage)  : 2458600.12560
            P (Orbital period in years)     : 3388.68

            Epoch                           : 2025 Sep 17
            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 15.40 + 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
2025-09-18 00:00 UT   06 36 22.0   +40 19 14    17.721   17.545   78.3    3.2   277   34.1 
2025-09-18 14:25 UT   06 36 23.7   +40 19 35    17.714   17.548   78.9    3.2   277   34.1 
2025-09-19 00:00 UT   06 36 24.7   +40 19 49    17.710   17.550   79.2    3.2   277   34.1 
2025-09-20 00:00 UT   06 36 27.1   +40 20 24    17.699   17.556   80.1    3.2   277   34.1 
2025-09-21 00:00 UT   06 36 29.1   +40 21 00    17.688   17.561   81.1    3.2   277   34.1 
2025-09-22 00:00 UT   06 36 30.9   +40 21 36    17.677   17.566   82.0    3.2   276   34.1 
2025-09-23 00:00 UT   06 36 32.4   +40 22 13    17.667   17.572   82.9    3.2   276   34.1 
2025-09-24 00:00 UT   06 36 33.6   +40 22 50    17.656   17.577   83.9    3.3   276   34.1 
2025-09-25 00:00 UT   06 36 34.5   +40 23 28    17.645   17.583   84.8    3.3   275   34.1 
2025-09-26 00:00 UT   06 36 35.1   +40 24 05    17.634   17.588   85.7    3.3   275   34.1 
2025-09-27 00:00 UT   06 36 35.4   +40 24 44    17.622   17.593   86.7    3.3   275   34.1 
2025-09-28 00:00 UT   06 36 35.4   +40 25 22    17.611   17.599   87.6    3.3   275   34.1 

    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.