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 Jan 2026	27.3	12.126 AU	12.031 AU	14h29m	+27°59'	93.2°	4.6°	292°

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
2026-01-17 00:00 UT   14 29 47.3   +27 54 56    12.039   12.118   92.2    4.7   292   27.3 
2026-01-18 00:00 UT   14 29 51.1   +27 58 40    12.032   12.124   93.0    4.6   292   27.3 
2026-01-18 04:47 UT   14 29 51.8   +27 59 25    12.031   12.126   93.2    4.6   292   27.3 
2026-01-19 00:00 UT   14 29 54.5   +28 02 26    12.026   12.131   93.8    4.6   291   27.3 
2026-01-20 00:00 UT   14 29 57.5   +28 06 14    12.019   12.137   94.6    4.6   291   27.3 
2026-01-21 00:00 UT   14 30 00.2   +28 10 04    12.012   12.144   95.4    4.6   290   27.3 
2026-01-22 00:00 UT   14 30 02.5   +28 13 56    12.005   12.151   96.2    4.6   289   27.3 
2026-01-23 00:00 UT   14 30 04.5   +28 17 50    11.999   12.157   96.9    4.6   289   27.3 
2026-01-24 00:00 UT   14 30 06.1   +28 21 46    11.992   12.164   97.7    4.6   288   27.3 
2026-01-25 00:00 UT   14 30 07.3   +28 25 44    11.985   12.171   98.5    4.6   287   27.3 
2026-01-26 00:00 UT   14 30 08.1   +28 29 44    11.979   12.177   99.3    4.6   286   27.3 
2026-01-27 00:00 UT   14 30 08.6   +28 33 45    11.973   12.184  100.1    4.6   286   27.3 
2026-01-28 00:00 UT   14 30 08.7   +28 37 48    11.966   12.190  100.8    4.6   285   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.