C/2020 X2 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	17 Nov 2020	18.9	3.836 AU	3.125 AU	07h02m	+17°55'	130.0°	11.4°	280°
Nearest approach	30 Dec 2020	18.7	3.850 AU	2.868 AU	06h48m	+20°54'	176.7°	0.8°	314°
Today	13 Jan 2026	26.8	11.899 AU	12.175 AU	15h00m	+00°04'	71.5°	4.5°	293°

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 based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (10.6 + 5 log[∆] + 10.0 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/2020 X2 (ATLAS) are:

    e (Eccentricity)                : 0.7683820
    q (Perihelion distance)         : 3.8355620
    i (Inclination)                 : 18.18710
    Ω (Longitude of ascending node) : 105.35130
    ω (Argument of perihelion)      : 347.62260
    L (Longitude of perihelion)     : 93.57454
    B (Latitude of perihelion)      : -3.83613
    T (Time of perihelion passage)  : 2459170.79950
    P (Orbital period in years)     : 67.39

    Epoch                           : 2026 Jan 13
    Reference                       : MPEC 2024-A43

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); Halley type (P < 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-01-12 00:00 UT   15 00 24.0   +00 04 19    12.196   11.892   69.7    4.4   293   26.8 
2026-01-13 00:00 UT   15 00 35.8   +00 04 38    12.185   11.896   70.6    4.5   293   26.8 
2026-01-13 21:18 UT   15 00 46.0   +00 04 56    12.175   11.899   71.5    4.5   293   26.8 
2026-01-14 00:00 UT   15 00 47.2   +00 04 59    12.174   11.900   71.6    4.5   293   26.8 
2026-01-15 00:00 UT   15 00 58.4   +00 05 22    12.163   11.904   72.5    4.5   292   26.8 
2026-01-16 00:00 UT   15 01 09.3   +00 05 46    12.151   11.908   73.4    4.5   292   26.8 
2026-01-17 00:00 UT   15 01 19.9   +00 06 13    12.140   11.913   74.4    4.6   292   26.8 
2026-01-18 00:00 UT   15 01 30.2   +00 06 42    12.128   11.917   75.3    4.6   291   26.8 
2026-01-19 00:00 UT   15 01 40.3   +00 07 13    12.116   11.921   76.2    4.6   291   26.8 
2026-01-20 00:00 UT   15 01 50.0   +00 07 45    12.105   11.925   77.2    4.6   291   26.8 
2026-01-21 00:00 UT   15 01 59.4   +00 08 19    12.093   11.929   78.1    4.6   291   26.8 
2026-01-22 00:00 UT   15 02 08.5   +00 08 56    12.081   11.934   79.1    4.6   290   26.8 
2026-01-23 00:00 UT   15 02 17.4   +00 09 34    12.069   11.938   80.0    4.7   290   26.8 

    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.