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	18 Jul 2025	32.9	20.786 AU	20.628 AU	07h32m	-76°34'	97.5°	2.8°	185°

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/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)
        

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 (14.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 12.63 + 5 log[∆] + 10.39 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
2025-07-18 00:00 UT   07 31 24.5   -76 34 37    20.620   20.781   97.7    2.8   184   32.9 
2025-07-18 23:00 UT   07 32 09.9   -76 34 41    20.628   20.786   97.5    2.8   185   32.9 
2025-07-19 00:00 UT   07 32 11.9   -76 34 41    20.628   20.786   97.5    2.8   185   32.9 
2025-07-20 00:00 UT   07 32 59.2   -76 34 47    20.636   20.792   97.4    2.8   186   32.9 
2025-07-21 00:00 UT   07 33 46.4   -76 34 55    20.645   20.797   97.2    2.8   186   32.9 
2025-07-22 00:00 UT   07 34 33.6   -76 35 05    20.653   20.802   97.0    2.8   187   32.9 
2025-07-23 00:00 UT   07 35 20.6   -76 35 18    20.661   20.808   96.9    2.8   188   32.9 
2025-07-24 00:00 UT   07 36 07.4   -76 35 33    20.669   20.813   96.7    2.8   189   32.9 
2025-07-25 00:00 UT   07 36 54.2   -76 35 51    20.678   20.818   96.5    2.8   189   32.9 
2025-07-26 00:00 UT   07 37 40.8   -76 36 10    20.686   20.823   96.3    2.8   190   32.9 
2025-07-27 00:00 UT   07 38 27.3   -76 36 32    20.695   20.829   96.1    2.8   191   32.9 
2025-07-28 00:00 UT   07 39 13.6   -76 36 56    20.703   20.834   96.0    2.8   192   32.9 

    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.