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°32'	75.2°	48.2°	178°
Today	28 Oct 2025	27.3	11.576 AU	12.334 AU	14h10m	+25°39'	38.7°	3.1°	1°

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)                : 1.0005260
    q (Perihelion distance)         : 1.2432140
    i (Inclination)                 : 117.49860
    Ω (Longitude of ascending node) : 223.19260
    ω (Argument of perihelion)      : 263.50500
    L (Longitude of perihelion)     : 147.04364
    B (Latitude of perihelion)      : -61.80309
    T (Time of perihelion passage)  : 2459738.91540

    Epoch                           : 2025 Oct 27
    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
2025-10-27 00:00 UT   14 10 17.3   +25 39 39    12.331   11.568   38.4    3.1     2   27.3 
2025-10-28 00:00 UT   14 10 37.0   +25 39 08    12.334   11.575   38.7    3.1     1   27.3 
2025-10-28 01:29 UT   14 10 38.2   +25 39 06    12.334   11.576   38.7    3.1     1   27.3 
2025-10-29 00:00 UT   14 10 56.6   +25 38 40    12.337   11.582   39.0    3.1   359   27.3 
2025-10-30 00:00 UT   14 11 16.2   +25 38 15    12.339   11.589   39.3    3.1   358   27.3 
2025-10-31 00:00 UT   14 11 35.8   +25 37 52    12.342   11.595   39.7    3.1   357   27.3 
2025-11-01 00:00 UT   14 11 55.4   +25 37 33    12.344   11.602   40.1    3.2   355   27.3 
2025-11-02 00:00 UT   14 12 14.9   +25 37 17    12.346   11.609   40.5    3.2   354   27.3 
2025-11-03 00:00 UT   14 12 34.4   +25 37 04    12.347   11.616   40.9    3.2   353   27.3 
2025-11-04 00:00 UT   14 12 53.9   +25 36 55    12.349   11.623   41.3    3.2   351   27.3 
2025-11-05 00:00 UT   14 13 13.3   +25 36 48    12.350   11.629   41.7    3.3   350   27.3 
2025-11-06 00:00 UT   14 13 32.6   +25 36 44    12.351   11.636   42.2    3.3   349   27.3 
2025-11-07 00:00 UT   14 13 52.0   +25 36 44    12.352   11.643   42.6    3.3   348   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.