A/2021 X2
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	8 Jul 2022	22.2	2.998 AU	3.517 AU	03h36m	+11°24'	51.9°	15.5°	250°
Nearest approach	4 Oct 2022	21.1	3.123 AU	2.261 AU	02h24m	-21°40'	143.5°	11.0°	312°
Today	30 Dec 2025	26.9	10.720 AU	11.560 AU	18h07m	-52°33'	30.0°	2.6°	195°

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 displayed light curve is calculated under the assumption that the object remains inactive. (H=16.20; G=.15).

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 A/2021 X2 are:

    e (Eccentricity)                : 1.0016940
    q (Perihelion distance)         : 2.9983450
    i (Inclination)                 : 137.14830
    Ω (Longitude of ascending node) : 228.85290
    ω (Argument of perihelion)      : 193.40550
    L (Longitude of perihelion)     : 218.94181
    B (Latitude of perihelion)      : -9.07203
    T (Time of perihelion passage)  : 2459769.00730

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2024-E08

    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   18 06 57.4   -52 34 20    11.552   10.709   29.7    2.6   191   26.9 
2025-12-30 00:00 UT   18 07 24.6   -52 34 04    11.556   10.715   29.9    2.6   193   26.9 
2025-12-30 19:50 UT   18 07 47.0   -52 33 52    11.560   10.720   30.0    2.6   195   26.9 
2025-12-31 00:00 UT   18 07 51.7   -52 33 49    11.561   10.721   30.1    2.6   195   26.9 
2026-01-01 00:00 UT   18 08 18.7   -52 33 37    11.565   10.728   30.3    2.7   197   27.0 
2026-01-02 00:00 UT   18 08 45.6   -52 33 28    11.569   10.734   30.6    2.7   198   27.0 
2026-01-03 00:00 UT   18 09 12.4   -52 33 20    11.572   10.740   30.9    2.7   200   27.0 
2026-01-04 00:00 UT   18 09 39.1   -52 33 15    11.576   10.747   31.2    2.7   202   27.0 
2026-01-05 00:00 UT   18 10 05.6   -52 33 12    11.579   10.753   31.5    2.7   203   27.0 
2026-01-06 00:00 UT   18 10 32.0   -52 33 11    11.582   10.759   31.8    2.8   205   27.0 
2026-01-07 00:00 UT   18 10 58.3   -52 33 12    11.584   10.766   32.2    2.8   207   27.0 
2026-01-08 00:00 UT   18 11 24.4   -52 33 16    11.587   10.772   32.6    2.8   208   27.0 
2026-01-09 00:00 UT   18 11 50.3   -52 33 22    11.589   10.778   33.0    2.9   210   27.0 

    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.