C/2017 T1 (Heinze)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	5 Jan 2018	10.0	1.154 AU	0.217 AU	05h35m	+61°49'	137.9°	34.8°	149°
Perihelion	22 Feb 2018	10.6	0.575 AU	1.226 AU	21h40m	+15°21'	27.5°	52.7°	337°
Today	11 Jul 2026	33.5	22.618 AU	22.451 AU	07h24m	-75°57'	98.1°	2.6°	179°

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)                : 0.9998480
    q (Perihelion distance)         : 0.5753040
    i (Inclination)                 : 97.01840
    Ω (Longitude of ascending node) : 103.00210
    ω (Argument of perihelion)      : 96.92730
    L (Longitude of perihelion)     : 148.16464
    B (Latitude of perihelion)      : 80.15089
    T (Time of perihelion passage)  : 2458172.05050
    P (Orbital period in years)     : 232852.39

    Epoch                           : 2026 May 29
    Reference                       : MPC194153

    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
2026-07-10 00:00 UT   07 23 25.4   -75 58 02    22.441   22.611   98.3    2.6   178   33.5 
2026-07-11 00:00 UT   07 24 07.5   -75 57 50    22.449   22.616   98.1    2.6   179   33.5 
2026-07-11 08:50 UT   07 24 22.9   -75 57 46    22.451   22.618   98.1    2.6   179   33.5 
2026-07-12 00:00 UT   07 24 49.5   -75 57 40    22.456   22.621   98.0    2.6   180   33.5 
2026-07-13 00:00 UT   07 25 31.5   -75 57 32    22.464   22.626   97.9    2.6   181   33.5 
2026-07-14 00:00 UT   07 26 13.5   -75 57 27    22.471   22.631   97.7    2.6   181   33.5 
2026-07-15 00:00 UT   07 26 55.5   -75 57 23    22.479   22.636   97.6    2.6   182   33.5 
2026-07-16 00:00 UT   07 27 37.3   -75 57 22    22.486   22.641   97.4    2.6   183   33.5 
2026-07-17 00:00 UT   07 28 19.1   -75 57 22    22.494   22.646   97.3    2.6   184   33.5 
2026-07-18 00:00 UT   07 29 00.9   -75 57 25    22.502   22.651   97.1    2.6   184   33.5 
2026-07-19 00:00 UT   07 29 42.5   -75 57 31    22.510   22.656   97.0    2.6   185   33.5 
2026-07-20 00:00 UT   07 30 24.1   -75 57 38    22.518   22.661   96.8    2.6   186   33.5 
2026-07-21 00:00 UT   07 31 05.5   -75 57 47    22.525   22.666   96.6    2.6   187   33.5 

    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.