C/2020 S8 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	10 Apr 2021	15.7	2.356 AU	1.468 AU	15h04m	+15°11'	144.4°	14.3°	231°
Nearest approach	23 Apr 2021	15.7	2.360 AU	1.411 AU	14h10m	+12°37'	154.8°	10.4°	185°
Today	26 Apr 2025	27.6	12.249 AU	12.660 AU	04h51m	-38°30'	63.7°	4.2°	136°

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.)

The orbital elements of C/2020 S8 (Lemmon) are:

            e (Eccentricity)                : 0.9902010
            q (Perihelion distance)         : 2.3559020
            i (Inclination)                 : 108.54060
            Ω (Longitude of ascending node) : 24.01710
            ω (Argument of perihelion)      : 160.13810
            L (Longitude of perihelion)     : 30.56976
            B (Latitude of perihelion)      : 18.79121
            T (Time of perihelion passage)  : 2459314.91740
            P (Orbital period in years)     : 3727.89

            Epoch                           : 2025 Apr 24
            Reference                       : MPEC 2021-P47

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (12.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 11.19 + 5 log[∆] + 10.00 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-04-26 00:00 UT   04 51 51.7   -38 30 40    12.659   12.248   63.8    4.2   136   27.6 
2025-04-26 02:27 UT   04 51 53.3   -38 30 20    12.660   12.249   63.7    4.2   136   27.6 
2025-04-27 00:00 UT   04 52 07.0   -38 27 31    12.670   12.254   63.5    4.2   137   27.6 
2025-04-28 00:00 UT   04 52 22.4   -38 24 27    12.680   12.261   63.3    4.2   138   27.6 
2025-04-29 00:00 UT   04 52 38.1   -38 21 25    12.690   12.267   63.1    4.2   139   27.6 
2025-04-30 00:00 UT   04 52 53.9   -38 18 27    12.700   12.273   62.8    4.2   140   27.6 
2025-05-01 00:00 UT   04 53 09.9   -38 15 32    12.709   12.279   62.6    4.2   141   27.6 
2025-05-02 00:00 UT   04 53 26.1   -38 12 41    12.719   12.285   62.4    4.2   142   27.6 
2025-05-03 00:00 UT   04 53 42.5   -38 09 53    12.729   12.291   62.2    4.2   143   27.6 
2025-05-04 00:00 UT   04 53 59.0   -38 07 09    12.738   12.298   62.0    4.2   144   27.6 
2025-05-05 00:00 UT   04 54 15.7   -38 04 28    12.747   12.304   61.8    4.1   145   27.6 
2025-05-06 00:00 UT   04 54 32.6   -38 01 50    12.756   12.310   61.6    4.1   146   27.6 

    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.