C/2016 U1 (NEOWISE)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	12 Dec 2016	10.4	0.901 AU	0.728 AU	15h22m	+31°53'	61.4°	73.5°	330°
Perihelion	13 Jan 2017	6.8	0.325 AU	1.162 AU	18h37m	-19°42'	14.6°	49.6°	280°
Today	26 Dec 2025	32.5	23.982 AU	23.471 AU	02h47m	-07°01'	120.2°	2.0°	58°

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 11.5 + 5 log[∆] + 10.3 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/2016 U1 (NEOWISE) are:

    e (Eccentricity)                : 1.0003900
    q (Perihelion distance)         : 0.3251450
    i (Inclination)                 : 46.16610
    Ω (Longitude of ascending node) : 61.68200
    ω (Argument of perihelion)      : 162.77110
    L (Longitude of perihelion)     : 49.56076
    B (Latitude of perihelion)      : 12.33673
    T (Time of perihelion passage)  : 2457766.82060

    Epoch                           : 2022 Jan 22
    Reference                       : MPC103847

    Classification(s):              : Nearly isotropic; New (a > 10000 AU)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-25 00:00 UT   02 48 00.1   -07 02 06    23.449   23.976  121.3    2.0    57   32.5 
2025-12-26 00:00 UT   02 47 53.9   -07 01 42    23.467   23.981  120.4    2.0    58   32.5 
2025-12-26 05:29 UT   02 47 52.5   -07 01 37    23.471   23.982  120.2    2.0    58   32.5 
2025-12-27 00:00 UT   02 47 47.9   -07 01 17    23.486   23.986  119.5    2.0    58   32.5 
2025-12-28 00:00 UT   02 47 42.0   -07 00 51    23.505   23.991  118.5    2.1    59   32.5 
2025-12-29 00:00 UT   02 47 36.2   -07 00 23    23.524   23.996  117.6    2.1    59   32.5 
2025-12-30 00:00 UT   02 47 30.6   -06 59 55    23.543   24.001  116.7    2.1    60   32.6 
2025-12-31 00:00 UT   02 47 25.2   -06 59 25    23.562   24.006  115.7    2.1    60   32.6 
2026-01-01 00:00 UT   02 47 19.9   -06 58 54    23.581   24.011  114.8    2.1    61   32.6 
2026-01-02 00:00 UT   02 47 14.8   -06 58 22    23.601   24.016  113.8    2.1    61   32.6 
2026-01-03 00:00 UT   02 47 09.8   -06 57 49    23.620   24.021  112.9    2.2    62   32.6 
2026-01-04 00:00 UT   02 47 04.9   -06 57 14    23.640   24.025  111.9    2.2    62   32.6 
2026-01-05 00:00 UT   02 47 00.2   -06 56 39    23.660   24.030  111.0    2.2    62   32.6 

    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.