C/2020 F7 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	15 Feb 2021	18.0	5.701 AU	4.781 AU	08h58m	-06°13'	156.5°	4.0°	36°
Perihelion	14 Nov 2021	17.9	5.337 AU	5.378 AU	09h05m	-33°35'	82.3°	10.6°	287°
Today	15 Mar 2026	23.2	11.841 AU	12.558 AU	22h59m	-43°19'	42.2°	3.2°	195°

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. The light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (7.0 + 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 F7 (Lemmon) are:

    e (Eccentricity)                : 0.9910640
    q (Perihelion distance)         : 5.3367220
    i (Inclination)                 : 93.99620
    Ω (Longitude of ascending node) : 321.81080
    ω (Argument of perihelion)      : 228.01360
    L (Longitude of perihelion)     : 317.38289
    B (Latitude of perihelion)      : -47.85904
    T (Time of perihelion passage)  : 2459532.72590
    P (Orbital period in years)     : 14594.77

    Epoch                           : 2026 Mar 14
    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
2026-03-14 00:00 UT   22 58 31.8   -43 22 28    12.560   11.833   41.4    3.2   194   23.2 
2026-03-15 00:00 UT   22 58 51.5   -43 20 30    12.559   11.838   41.9    3.2   195   23.2 
2026-03-15 13:50 UT   22 59 02.8   -43 19 23    12.558   11.841   42.2    3.2   195   23.2 
2026-03-16 00:00 UT   22 59 11.1   -43 18 34    12.558   11.843   42.4    3.2   196   23.2 
2026-03-17 00:00 UT   22 59 30.5   -43 16 41    12.557   11.848   42.9    3.3   197   23.2 
2026-03-18 00:00 UT   22 59 49.9   -43 14 52    12.555   11.853   43.5    3.3   198   23.2 
2026-03-19 00:00 UT   23 00 09.2   -43 13 05    12.554   11.859   44.0    3.3   199   23.2 
2026-03-20 00:00 UT   23 00 28.3   -43 11 21    12.552   11.864   44.6    3.4   200   23.2 
2026-03-21 00:00 UT   23 00 47.3   -43 09 41    12.550   11.869   45.2    3.4   201   23.2 
2026-03-22 00:00 UT   23 01 06.2   -43 08 03    12.548   11.874   45.7    3.4   202   23.2 
2026-03-23 00:00 UT   23 01 25.0   -43 06 28    12.545   11.879   46.3    3.5   203   23.2 
2026-03-24 00:00 UT   23 01 43.6   -43 04 57    12.543   11.885   46.9    3.5   204   23.2 
2026-03-25 00:00 UT   23 02 02.1   -43 03 28    12.540   11.890   47.5    3.5   205   23.2 

    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.