C/2020 J1 (SONEAR)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	17 Apr 2021	13.0	3.344 AU	2.597 AU	16h43m	-36°52'	131.1°	13.1°	291°
Nearest approach	16 May 2021	12.8	3.355 AU	2.355 AU	15h23m	-29°14'	169.7°	3.1°	12°
Today	23 Aug 2026	24.2	14.572 AU	15.287 AU	09h00m	+53°03'	43.6°	2.7°	336°

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 4.9 + 5 log[∆] + 11.5 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)                : 0.9989750
    q (Perihelion distance)         : 3.3437540
    i (Inclination)                 : 142.31340
    Ω (Longitude of ascending node) : 226.53620
    ω (Argument of perihelion)      : 341.49370
    L (Longitude of perihelion)     : 241.37223
    B (Latitude of perihelion)      : -11.18896
    T (Time of perihelion passage)  : 2459321.68550
    P (Orbital period in years)     : 186322.66

    Epoch                           : 2026 Aug 13
    Reference                       : MPC194167

    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
2026-08-22 00:00 UT   09 00 02.5   +53 03 57    15.289   14.565   43.0    2.7   337   24.2 
2026-08-23 00:00 UT   09 00 21.1   +53 03 58    15.287   14.571   43.5    2.7   336   24.2 
2026-08-23 03:39 UT   09 00 24.0   +53 03 58    15.287   14.572   43.6    2.7   336   24.2 
2026-08-24 00:00 UT   09 00 39.7   +53 04 01    15.286   14.577   44.0    2.8   335   24.2 
2026-08-25 00:00 UT   09 00 58.1   +53 04 06    15.284   14.582   44.6    2.8   334   24.2 
2026-08-26 00:00 UT   09 01 16.5   +53 04 14    15.282   14.588   45.1    2.8   333   24.2 
2026-08-27 00:00 UT   09 01 34.6   +53 04 24    15.280   14.593   45.7    2.8   332   24.2 
2026-08-28 00:00 UT   09 01 52.7   +53 04 36    15.278   14.599   46.3    2.9   331   24.2 
2026-08-29 00:00 UT   09 02 10.6   +53 04 50    15.276   14.605   46.9    2.9   330   24.2 
2026-08-30 00:00 UT   09 02 28.3   +53 05 07    15.273   14.610   47.5    2.9   329   24.2 
2026-08-31 00:00 UT   09 02 45.9   +53 05 26    15.270   14.616   48.1    2.9   328   24.2 
2026-09-01 00:00 UT   09 03 03.4   +53 05 47    15.267   14.621   48.7    3.0   327   24.2 
2026-09-02 00:00 UT   09 03 20.7   +53 06 11    15.264   14.627   49.3    3.0   327   24.2 

    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.