C/2020 J1 (SONEAR)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	17 Apr 2021	13.0	3.344 AU	2.599 AU	16h44m	-36°52'	130.9°	13.1°	291°
Nearest approach	16 May 2021	12.8	3.355 AU	2.355 AU	15h23m	-29°13'	169.7°	3.1°	12°
Today	18 Oct 2026	24.3	14.885 AU	14.962 AU	09h12m	+54°07'	83.6°	3.8°	296°

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)                : 0.9988970
    q (Perihelion distance)         : 3.3437440
    i (Inclination)                 : 142.31470
    Ω (Longitude of ascending node) : 226.52840
    ω (Argument of perihelion)      : 341.48330
    L (Longitude of perihelion)     : 241.37323
    B (Latitude of perihelion)      : -11.19478
    T (Time of perihelion passage)  : 2459321.54710
    P (Orbital period in years)     : 166911.50

    Epoch                           : 2026 Oct 17
    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
2026-10-17 00:00 UT   09 12 04.4   +54 04 14    14.975   14.877   82.5    3.8   297   24.3 
2026-10-18 00:00 UT   09 12 08.5   +54 06 22    14.966   14.883   83.3    3.8   296   24.3 
2026-10-18 10:30 UT   09 12 10.1   +54 07 19    14.962   14.885   83.6    3.8   296   24.3 
2026-10-19 00:00 UT   09 12 12.2   +54 08 32    14.958   14.888   84.1    3.8   296   24.3 
2026-10-20 00:00 UT   09 12 15.5   +54 10 44    14.949   14.894   84.9    3.8   295   24.3 
2026-10-21 00:00 UT   09 12 18.4   +54 12 58    14.940   14.899   85.7    3.8   295   24.3 
2026-10-22 00:00 UT   09 12 20.9   +54 15 14    14.932   14.905   86.5    3.8   294   24.3 
2026-10-23 00:00 UT   09 12 22.9   +54 17 32    14.923   14.910   87.3    3.8   293   24.3 
2026-10-24 00:00 UT   09 12 24.5   +54 19 52    14.915   14.916   88.1    3.8   293   24.3 
2026-10-25 00:00 UT   09 12 25.7   +54 22 13    14.906   14.921   89.0    3.8   292   24.3 
2026-10-26 00:00 UT   09 12 26.5   +54 24 36    14.897   14.927   89.8    3.8   292   24.3 
2026-10-27 00:00 UT   09 12 26.8   +54 27 00    14.889   14.933   90.6    3.8   291   24.3 
2026-10-28 00:00 UT   09 12 26.7   +54 29 27    14.880   14.938   91.4    3.8   291   24.3 

    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.