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	15 Dec 2025	26.9	10.623 AU	11.464 AU	18h00m	-52°41'	30.0°	2.7°	166°

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
2025-12-14 00:00 UT   18 00 02.8   -52 43 04    11.452   10.614   30.3    2.7   164   26.9 
2025-12-15 00:00 UT   18 00 30.6   -52 42 13    11.460   10.620   30.1    2.7   165   26.9 
2025-12-15 11:45 UT   18 00 44.2   -52 41 49    11.464   10.623   30.0    2.7   166   26.9 
2025-12-16 00:00 UT   18 00 58.3   -52 41 24    11.468   10.627   29.9    2.6   167   26.9 
2025-12-17 00:00 UT   18 01 26.1   -52 40 38    11.476   10.633   29.7    2.6   169   26.9 
2025-12-18 00:00 UT   18 01 53.9   -52 39 53    11.484   10.639   29.5    2.6   171   26.9 
2025-12-19 00:00 UT   18 02 21.6   -52 39 12    11.491   10.646   29.4    2.6   173   26.9 
2025-12-20 00:00 UT   18 02 49.4   -52 38 32    11.499   10.652   29.3    2.6   175   26.9 
2025-12-21 00:00 UT   18 03 17.1   -52 37 55    11.505   10.658   29.2    2.6   176   26.9 
2025-12-22 00:00 UT   18 03 44.9   -52 37 20    11.512   10.665   29.2    2.6   178   26.9 
2025-12-23 00:00 UT   18 04 12.5   -52 36 47    11.519   10.671   29.2    2.6   180   26.9 
2025-12-24 00:00 UT   18 04 40.2   -52 36 17    11.525   10.677   29.2    2.6   182   26.9 
2025-12-25 00:00 UT   18 05 07.8   -52 35 49    11.531   10.684   29.2    2.6   184   26.9 

    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.