C/2020 S8 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	10 Apr 2021	15.7	2.356 AU	1.469 AU	15h05m	+15°08'	144.1°	14.4°	232°
Nearest approach	22 Apr 2021	15.7	2.360 AU	1.410 AU	14h10m	+12°33'	154.9°	10.4°	185°
Today	4 Nov 2026	29.0	15.508 AU	15.048 AU	04h50m	-40°41'	116.0°	3.3°	324°

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 11.2 + 5 log[∆] + 10.0 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 S8 (Lemmon) are:

    e (Eccentricity)                : 0.9899600
    q (Perihelion distance)         : 2.3555200
    i (Inclination)                 : 108.56680
    Ω (Longitude of ascending node) : 23.94660
    ω (Argument of perihelion)      : 160.09570
    L (Longitude of perihelion)     : 30.52319
    B (Latitude of perihelion)      : 18.82815
    T (Time of perihelion passage)  : 2459314.51500
    P (Orbital period in years)     : 3593.60

    Epoch                           : 2026 May 29
    Reference                       : MPC194170

    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
2026-11-03 00:00 UT   04 50 53.9   -40 39 28    15.044   15.500  115.7    3.3   322   29.0 
2026-11-04 00:00 UT   04 50 33.8   -40 41 11    15.047   15.506  115.9    3.3   323   29.0 
2026-11-04 09:36 UT   04 50 25.7   -40 41 51    15.048   15.508  116.0    3.3   324   29.0 
2026-11-05 00:00 UT   04 50 13.4   -40 42 50    15.049   15.512  116.1    3.3   324   29.0 
2026-11-06 00:00 UT   04 49 52.9   -40 44 26    15.053   15.517  116.3    3.3   326   29.0 
2026-11-07 00:00 UT   04 49 32.2   -40 45 59    15.056   15.523  116.4    3.3   327   29.0 
2026-11-08 00:00 UT   04 49 11.3   -40 47 29    15.059   15.528  116.6    3.3   328   29.0 
2026-11-09 00:00 UT   04 48 50.2   -40 48 55    15.063   15.534  116.7    3.3   329   29.0 
2026-11-10 00:00 UT   04 48 29.0   -40 50 17    15.066   15.540  116.9    3.3   330   29.0 
2026-11-11 00:00 UT   04 48 07.6   -40 51 36    15.070   15.545  117.0    3.3   332   29.0 
2026-11-12 00:00 UT   04 47 46.0   -40 52 52    15.074   15.551  117.1    3.2   333   29.0 
2026-11-13 00:00 UT   04 47 24.3   -40 54 03    15.079   15.556  117.2    3.2   334   29.0 
2026-11-14 00:00 UT   04 47 02.4   -40 55 12    15.083   15.562  117.3    3.2   335   29.0 

    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.