C/2021 T2 (Fuls)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	8 Jun 2022	17.8	1.243 AU	1.471 AU	03h42m	-30°08'	56.5°	42.9°	203°
Nearest approach	6 Jul 2022	17.4	1.318 AU	1.138 AU	07h11m	-52°31'	75.2°	48.2°	178°
Today	30 Dec 2025	27.3	12.000 AU	12.160 AU	14h27m	+26°55'	78.3°	4.6°	304°

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. The light curve is estimated manually by the author. (16.5 + 5 log[∆] + 5.0 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/2021 T2 (Fuls) are:

    e (Eccentricity)                : 1.0005230
    q (Perihelion distance)         : 1.2431040
    i (Inclination)                 : 117.49650
    Ω (Longitude of ascending node) : 223.19020
    ω (Argument of perihelion)      : 263.50190
    L (Longitude of perihelion)     : 147.04859
    B (Latitude of perihelion)      : -61.80447
    T (Time of perihelion passage)  : 2459738.92280

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2023-A50

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-29 00:00 UT   14 27 31.4   +26 52 07    12.169   11.991   77.3    4.6   305   27.3 
2025-12-30 00:00 UT   14 27 41.4   +26 55 01    12.162   11.998   78.1    4.6   304   27.3 
2025-12-30 07:05 UT   14 27 44.3   +26 55 53    12.160   12.000   78.3    4.6   304   27.3 
2025-12-31 00:00 UT   14 27 51.1   +26 57 57    12.156   12.005   78.8    4.6   303   27.3 
2026-01-01 00:00 UT   14 28 00.5   +27 00 56    12.149   12.011   79.6    4.6   303   27.3 
2026-01-02 00:00 UT   14 28 09.6   +27 03 59    12.142   12.018   80.4    4.6   302   27.3 
2026-01-03 00:00 UT   14 28 18.3   +27 07 04    12.136   12.025   81.2    4.6   301   27.3 
2026-01-04 00:00 UT   14 28 26.8   +27 10 12    12.129   12.031   82.0    4.6   301   27.3 
2026-01-05 00:00 UT   14 28 35.0   +27 13 22    12.122   12.038   82.7    4.6   300   27.3 
2026-01-06 00:00 UT   14 28 42.8   +27 16 36    12.115   12.045   83.5    4.7   300   27.3 
2026-01-07 00:00 UT   14 28 50.4   +27 19 52    12.108   12.051   84.3    4.7   299   27.3 
2026-01-08 00:00 UT   14 28 57.6   +27 23 11    12.101   12.058   85.1    4.7   298   27.3 
2026-01-09 00:00 UT   14 29 04.4   +27 26 32    12.094   12.065   85.9    4.7   298   27.3 

    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.