A/2020 A1
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	29 Nov 2019	21.1	1.674 AU	2.139 AU	12h43m	-26°23'	49.4°	26.6°	276°
Nearest approach	1 Feb 2020	19.0	1.862 AU	0.913 AU	09h07m	-05°23'	157.3°	11.8°	354°
Today	23 Nov 2025	29.2	15.582 AU	14.882 AU	00h37m	+39°56'	133.8°	2.6°	100°

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=17.10; 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/2020 A1 are:

    e (Eccentricity)                : 0.9342530
    q (Perihelion distance)         : 1.6737640
    i (Inclination)                 : 149.03150
    Ω (Longitude of ascending node) : 119.04770
    ω (Argument of perihelion)      : 302.40750
    L (Longitude of perihelion)     : 172.53375
    B (Latitude of perihelion)      : -25.74884
    T (Time of perihelion passage)  : 2458817.26670
    P (Orbital period in years)     : 128.45

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2023-A50

    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
2025-11-22 00:00 UT   00 38 19.2   +40 00 38    14.864   15.576  134.7    2.6   102   29.2 
2025-11-23 00:00 UT   00 38 05.0   +39 57 46    14.877   15.580  134.0    2.6   100   29.2 
2025-11-23 08:58 UT   00 37 59.8   +39 56 42    14.882   15.582  133.8    2.6   100   29.2 
2025-11-24 00:00 UT   00 37 51.1   +39 54 54    14.891   15.585  133.3    2.6    99   29.2 
2025-11-25 00:00 UT   00 37 37.6   +39 52 01    14.904   15.590  132.6    2.7    98   29.2 
2025-11-26 00:00 UT   00 37 24.3   +39 49 08    14.918   15.595  131.9    2.7    97   29.2 
2025-11-27 00:00 UT   00 37 11.4   +39 46 15    14.932   15.599  131.1    2.7    96   29.2 
2025-11-28 00:00 UT   00 36 58.8   +39 43 22    14.946   15.604  130.4    2.8    95   29.2 
2025-11-29 00:00 UT   00 36 46.4   +39 40 29    14.961   15.609  129.6    2.8    94   29.2 
2025-11-30 00:00 UT   00 36 34.5   +39 37 36    14.975   15.613  128.9    2.8    93   29.2 
2025-12-01 00:00 UT   00 36 22.8   +39 34 43    14.990   15.618  128.1    2.8    92   29.2 
2025-12-02 00:00 UT   00 36 11.4   +39 31 50    15.005   15.623  127.3    2.9    91   29.2 
2025-12-03 00:00 UT   00 36 00.4   +39 28 57    15.020   15.628  126.5    2.9    90   29.3 

    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.