C/2020 J1 (SONEAR)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	17 Apr 2021	12.9	3.344 AU	2.592 AU	16h43m	-36°52'	131.5°	13.0°	291°
Nearest approach	16 May 2021	12.8	3.355 AU	2.355 AU	15h24m	-29°16'	169.7°	3.1°	13°
Today	8 Mar 2026	23.9	13.623 AU	13.097 AU	08h50m	+57°54'	120.2°	3.6°	138°

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 4.5 + 5 log[∆] + 12.2 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 J1 (SONEAR) are:

    e (Eccentricity)                : 0.9992020
    q (Perihelion distance)         : 3.3436370
    i (Inclination)                 : 142.31020
    Ω (Longitude of ascending node) : 226.55900
    ω (Argument of perihelion)      : 341.52220
    L (Longitude of perihelion)     : 241.37099
    B (Latitude of perihelion)      : -11.17294
    T (Time of perihelion passage)  : 2459322.06700
    P (Orbital period in years)     : 271221.65

    Epoch                           : 2026 Mar 07
    Reference                       : MPEC 2026-E44

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-03-07 00:00 UT   08 51 03.8   +57 55 33    13.075   13.616  121.2    3.6   139   23.9 
2026-03-08 00:00 UT   08 50 31.0   +57 54 40    13.091   13.621  120.4    3.6   138   23.9 
2026-03-08 08:07 UT   08 50 20.0   +57 54 21    13.097   13.623  120.2    3.6   138   23.9 
2026-03-09 00:00 UT   08 49 58.6   +57 53 43    13.108   13.627  119.7    3.6   137   23.9 
2026-03-10 00:00 UT   08 49 26.7   +57 52 43    13.124   13.633  119.0    3.7   136   23.9 
2026-03-11 00:00 UT   08 48 55.3   +57 51 40    13.140   13.639  118.2    3.7   135   23.9 
2026-03-12 00:00 UT   08 48 24.3   +57 50 33    13.157   13.644  117.5    3.7   134   23.9 
2026-03-13 00:00 UT   08 47 53.8   +57 49 23    13.174   13.650  116.7    3.7   133   23.9 
2026-03-14 00:00 UT   08 47 23.8   +57 48 11    13.191   13.656  116.0    3.8   132   23.9 
2026-03-15 00:00 UT   08 46 54.3   +57 46 55    13.208   13.661  115.2    3.8   131   23.9 
2026-03-16 00:00 UT   08 46 25.3   +57 45 36    13.225   13.667  114.4    3.8   131   23.9 
2026-03-17 00:00 UT   08 45 56.9   +57 44 14    13.243   13.673  113.7    3.8   130   23.9 
2026-03-18 00:00 UT   08 45 28.9   +57 42 49    13.260   13.679  112.9    3.8   129   23.9 

    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.