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	18 Dec 2025	27.3	11.922 AU	12.234 AU	14h25m	+26°25'	69.3°	4.4°	311°

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
2025-12-17 00:00 UT   14 25 09.9   +26 21 28    12.243   11.911   68.1    4.4   312   27.3 
2025-12-18 00:00 UT   14 25 23.1   +26 23 44    12.237   11.918   68.9    4.4   312   27.3 
2025-12-18 13:13 UT   14 25 30.3   +26 25 00    12.234   11.922   69.3    4.4   311   27.3 
2025-12-19 00:00 UT   14 25 36.1   +26 26 03    12.231   11.925   69.6    4.4   311   27.3 
2025-12-20 00:00 UT   14 25 48.8   +26 28 25    12.225   11.931   70.4    4.5   310   27.3 
2025-12-21 00:00 UT   14 26 01.3   +26 30 51    12.219   11.938   71.1    4.5   310   27.3 
2025-12-22 00:00 UT   14 26 13.5   +26 33 19    12.213   11.945   71.9    4.5   309   27.3 
2025-12-23 00:00 UT   14 26 25.5   +26 35 51    12.207   11.951   72.7    4.5   308   27.3 
2025-12-24 00:00 UT   14 26 37.1   +26 38 26    12.201   11.958   73.4    4.5   308   27.3 
2025-12-25 00:00 UT   14 26 48.6   +26 41 04    12.195   11.965   74.2    4.5   307   27.3 
2025-12-26 00:00 UT   14 26 59.7   +26 43 45    12.188   11.971   75.0    4.6   307   27.3 
2025-12-27 00:00 UT   14 27 10.5   +26 46 30    12.182   11.978   75.7    4.6   306   27.3 
2025-12-28 00:00 UT   14 27 21.1   +26 49 17    12.175   11.985   76.5    4.6   305   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.