C/2017 T2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	28 Dec 2019	9.8	2.338 AU	1.527 AU	03h33m	+52°27'	136.2°	16.9°	115°
Perihelion	6 May 2020	8.6	1.601 AU	1.702 AU	07h03m	+75°16'	66.8°	35.4°	67°
Today	22 Jun 2026	22.7	17.346 AU	16.666 AU	20h06m	-69°16'	130.7°	2.5°	322°

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 5.7 + 5 log[∆] + 8.9 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 T2 (PANSTARRS) are:

    e (Eccentricity)                : 0.9991090
    q (Perihelion distance)         : 1.6008340
    i (Inclination)                 : 57.25090
    Ω (Longitude of ascending node) : 64.37680
    ω (Argument of perihelion)      : 92.78480
    L (Longitude of perihelion)     : 339.51491
    B (Latitude of perihelion)      : 57.14585
    T (Time of perihelion passage)  : 2458976.37610
    P (Orbital period in years)     : 76155.78

    Epoch                           : 2026 Jun 22
    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
2026-06-21 00:00 UT   20 07 07.4   -69 13 29    16.661   17.336  130.3    2.6   320   22.7 
2026-06-22 00:00 UT   20 06 37.5   -69 15 19    16.664   17.341  130.5    2.6   321   22.7 
2026-06-22 19:22 UT   20 06 13.1   -69 16 45    16.666   17.346  130.7    2.5   322   22.7 
2026-06-23 00:00 UT   20 06 07.2   -69 17 06    16.666   17.347  130.7    2.5   322   22.7 
2026-06-24 00:00 UT   20 05 36.6   -69 18 50    16.669   17.352  130.9    2.5   324   22.7 
2026-06-25 00:00 UT   20 05 05.6   -69 20 32    16.672   17.358  131.1    2.5   325   22.7 
2026-06-26 00:00 UT   20 04 34.2   -69 22 11    16.675   17.363  131.3    2.5   327   22.7 
2026-06-27 00:00 UT   20 04 02.5   -69 23 48    16.679   17.369  131.5    2.5   328   22.7 
2026-06-28 00:00 UT   20 03 30.4   -69 25 22    16.682   17.375  131.6    2.5   330   22.7 
2026-06-29 00:00 UT   20 02 58.1   -69 26 53    16.686   17.380  131.8    2.5   331   22.7 
2026-06-30 00:00 UT   20 02 25.4   -69 28 22    16.690   17.386  131.9    2.5   332   22.7 
2026-07-01 00:00 UT   20 01 52.4   -69 29 48    16.694   17.391  132.0    2.5   334   22.7 
2026-07-02 00:00 UT   20 01 19.2   -69 31 11    16.698   17.397  132.1    2.5   335   22.7 

    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.