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	5 Sep 2026	33.6	22.900 AU	22.926 AU	07h59m	-76°42'	87.2°	2.5°	224°

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
2026-09-04 00:00 UT   07 58 49.8   -76 39 55    22.912   22.892   87.6    2.5   222   33.6 
2026-09-05 00:00 UT   07 59 19.8   -76 41 34    22.921   22.897   87.3    2.5   223   33.6 
2026-09-05 13:43 UT   07 59 36.8   -76 42 31    22.926   22.900   87.2    2.5   224   33.6 
2026-09-06 00:00 UT   07 59 49.4   -76 43 14    22.930   22.902   87.1    2.5   224   33.6 
2026-09-07 00:00 UT   08 00 18.6   -76 44 56    22.939   22.907   86.9    2.5   225   33.6 
2026-09-08 00:00 UT   08 00 47.3   -76 46 40    22.948   22.912   86.7    2.5   226   33.6 
2026-09-09 00:00 UT   08 01 15.6   -76 48 25    22.957   22.917   86.5    2.5   227   33.6 
2026-09-10 00:00 UT   08 01 43.4   -76 50 12    22.966   22.922   86.2    2.5   227   33.6 
2026-09-11 00:00 UT   08 02 10.8   -76 52 00    22.975   22.927   86.0    2.5   228   33.6 
2026-09-12 00:00 UT   08 02 37.6   -76 53 50    22.983   22.932   85.8    2.5   229   33.6 
2026-09-13 00:00 UT   08 03 04.0   -76 55 41    22.992   22.937   85.6    2.5   230   33.6 
2026-09-14 00:00 UT   08 03 30.0   -76 57 34    23.001   22.942   85.4    2.5   231   33.6 
2026-09-15 00:00 UT   08 03 55.4   -76 59 28    23.010   22.947   85.1    2.5   232   33.6 

    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.