C/2017 T1 (Heinze)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	3 Jan 2018	10.0	1.150 AU	0.226 AU	06h16m	+69°12'	133.2°	38.6°	167°
Perihelion	20 Feb 2018	10.7	0.586 AU	1.233 AU	21h33m	+15°06'	27.9°	52.2°	338°
Today	7 Dec 2025	33.2	21.524 AU	21.779 AU	08h03m	-80°56'	73.7°	2.5°	315°

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 12.6 + 5 log[∆] + 10.4 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/2017 T1 (Heinze) are:

    e (Eccentricity)                : 0.9999450
    q (Perihelion distance)         : 0.5860040
    i (Inclination)                 : 96.93720
    Ω (Longitude of ascending node) : 102.65210
    ω (Argument of perihelion)      : 97.04450
    L (Longitude of perihelion)     : 146.99755
    B (Latitude of perihelion)      : 80.12545
    T (Time of perihelion passage)  : 2458170.12690

    Epoch                           : 2023 Apr 14
    Reference                       : MPC114600

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-06 00:00 UT   08 04 36.1   -80 54 02    21.771   21.516   73.7    2.5   314   33.2 
2025-12-07 00:00 UT   08 03 45.5   -80 55 51    21.776   21.522   73.7    2.5   315   33.2 
2025-12-07 09:51 UT   08 03 24.4   -80 56 34    21.779   21.524   73.7    2.5   315   33.2 
2025-12-08 00:00 UT   08 02 53.8   -80 57 37    21.781   21.527   73.7    2.5   316   33.2 
2025-12-09 00:00 UT   08 02 00.9   -80 59 20    21.786   21.532   73.7    2.5   317   33.2 
2025-12-10 00:00 UT   08 01 06.9   -81 01 01    21.791   21.537   73.8    2.5   319   33.2 
2025-12-11 00:00 UT   08 00 11.8   -81 02 39    21.796   21.542   73.8    2.5   320   33.2 
2025-12-12 00:00 UT   07 59 15.7   -81 04 15    21.800   21.547   73.8    2.5   321   33.2 
2025-12-13 00:00 UT   07 58 18.5   -81 05 48    21.805   21.553   73.9    2.5   322   33.2 
2025-12-14 00:00 UT   07 57 20.2   -81 07 18    21.809   21.558   73.9    2.5   324   33.2 
2025-12-15 00:00 UT   07 56 20.9   -81 08 45    21.814   21.563   73.9    2.5   325   33.2 
2025-12-16 00:00 UT   07 55 20.7   -81 10 10    21.818   21.568   74.0    2.5   326   33.2 
2025-12-17 00:00 UT   07 54 19.5   -81 11 31    21.822   21.573   74.0    2.5   328   33.2 

    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.