A/2020 A1
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	29 Nov 2019	21.1	1.677 AU	2.148 AU	12h42m	-26°13'	49.1°	26.4°	276°
Nearest approach	1 Feb 2020	19.0	1.867 AU	0.918 AU	09h07m	-05°10'	157.5°	11.7°	354°
Today	18 Jul 2026	29.7	16.677 AU	16.730 AU	01h00m	+40°09'	85.2°	3.5°	246°

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)                : 0.9341300
    q (Perihelion distance)         : 1.6773470
    i (Inclination)                 : 149.03150
    Ω (Longitude of ascending node) : 119.04120
    ω (Argument of perihelion)      : 302.43820
    L (Longitude of perihelion)     : 172.49481
    B (Latitude of perihelion)      : -25.73943
    T (Time of perihelion passage)  : 2458816.67180
    P (Orbital period in years)     : 128.50

    Epoch                           : 2026 May 29
    Reference                       : MPC194165

    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
2026-07-17 00:00 UT   01 00 26.2   +40 07 53    16.742   16.672   84.3    3.5   247   29.7 
2026-07-18 00:00 UT   01 00 21.7   +40 09 27    16.732   16.676   85.1    3.5   246   29.7 
2026-07-18 03:30 UT   01 00 21.0   +40 09 40    16.730   16.677   85.2    3.5   246   29.7 
2026-07-19 00:00 UT   01 00 16.9   +40 10 59    16.722   16.681   85.9    3.5   246   29.7 
2026-07-20 00:00 UT   01 00 11.8   +40 12 30    16.712   16.685   86.8    3.5   245   29.7 
2026-07-21 00:00 UT   01 00 06.4   +40 13 59    16.702   16.690   87.6    3.5   245   29.7 
2026-07-22 00:00 UT   01 00 00.7   +40 15 27    16.692   16.694   88.4    3.5   244   29.7 
2026-07-23 00:00 UT   00 59 54.8   +40 16 54    16.681   16.699   89.2    3.5   244   29.7 
2026-07-24 00:00 UT   00 59 48.5   +40 18 19    16.671   16.704   90.0    3.5   243   29.7 
2026-07-25 00:00 UT   00 59 42.0   +40 19 43    16.661   16.708   90.9    3.5   243   29.7 
2026-07-26 00:00 UT   00 59 35.1   +40 21 05    16.651   16.713   91.7    3.5   242   29.7 
2026-07-27 00:00 UT   00 59 28.0   +40 22 25    16.641   16.717   92.5    3.5   242   29.7 
2026-07-28 00:00 UT   00 59 20.6   +40 23 44    16.631   16.722   93.4    3.5   241   29.7 

    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.