C/2019 H1 (NEOWISE)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	26 Apr 2019	18.8	1.839 AU	1.447 AU	19h46m	+03°07'	95.4°	33.0°	256°
Nearest approach	21 May 2019	18.6	1.867 AU	1.226 AU	18h50m	+31°48'	112.8°	30.0°	225°
Today	24 Mar 2026	34.4	18.540 AU	18.565 AU	06h01m	+39°39'	87.0°	3.1°	89°

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 15.4 + 5 log[∆] + 10.0 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/2019 H1 (NEOWISE) are:

    e (Eccentricity)                : 0.9917000
    q (Perihelion distance)         : 1.8386890
    i (Inclination)                 : 104.36720
    Ω (Longitude of ascending node) : 269.30890
    ω (Argument of perihelion)      : 19.20780
    L (Longitude of perihelion)     : 264.36809
    B (Latitude of perihelion)      : 18.58469
    T (Time of perihelion passage)  : 2458599.61100
    P (Orbital period in years)     : 3297.20

    Epoch                           : 2026 Mar 16
    Reference                       : MPEC 2026-E44

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-03-23 00:00 UT   06 01 53.6   +39 40 59    18.532   18.532   88.4    3.1    90   34.4 
2026-03-24 00:00 UT   06 01 53.8   +39 39 46    18.553   18.537   87.5    3.1    89   34.4 
2026-03-24 13:13 UT   06 01 54.0   +39 39 06    18.565   18.540   87.0    3.1    89   34.4 
2026-03-25 00:00 UT   06 01 54.2   +39 38 33    18.575   18.542   86.5    3.1    89   34.4 
2026-03-26 00:00 UT   06 01 55.0   +39 37 21    18.597   18.548   85.6    3.1    89   34.4 
2026-03-27 00:00 UT   06 01 56.0   +39 36 09    18.619   18.553   84.6    3.1    89   34.4 
2026-03-28 00:00 UT   06 01 57.3   +39 34 57    18.641   18.558   83.7    3.1    88   34.4 
2026-03-29 00:00 UT   06 01 58.9   +39 33 45    18.662   18.563   82.7    3.1    88   34.4 
2026-03-30 00:00 UT   06 02 00.8   +39 32 34    18.684   18.568   81.8    3.1    88   34.4 
2026-03-31 00:00 UT   06 02 02.9   +39 31 23    18.706   18.574   80.9    3.0    88   34.4 
2026-04-01 00:00 UT   06 02 05.3   +39 30 12    18.727   18.579   79.9    3.0    87   34.5 
2026-04-02 00:00 UT   06 02 08.0   +39 29 02    18.749   18.584   79.0    3.0    87   34.5 
2026-04-03 00:00 UT   06 02 11.0   +39 27 51    18.770   18.589   78.0    3.0    87   34.5 

    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.