C/2020 F7 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	15 Feb 2021	18.0	5.703 AU	4.783 AU	08h58m	-06°13'	156.5°	4.0°	36°
Perihelion	14 Nov 2021	17.9	5.338 AU	5.375 AU	09h05m	-33°38'	82.5°	10.6°	287°
Today	14 Aug 2026	23.4	12.627 AU	11.788 AU	22h52m	-45°54'	144.5°	2.7°	326°

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)                : 0.9913640
    q (Perihelion distance)         : 5.3378400
    i (Inclination)                 : 94.00050
    Ω (Longitude of ascending node) : 321.80780
    ω (Argument of perihelion)      : 228.03390
    L (Longitude of perihelion)     : 317.37200
    B (Latitude of perihelion)      : -47.87890
    T (Time of perihelion passage)  : 2459533.01790
    P (Orbital period in years)     : 15366.66

    Epoch                           : 2026 Aug 13
    Reference                       : MPC194166

    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
2026-08-13 00:00 UT   22 53 05.7   -45 52 47    11.783   12.621  144.3    2.7   324   23.4 
2026-08-14 00:00 UT   22 52 36.8   -45 54 07    11.787   12.626  144.5    2.7   326   23.4 
2026-08-14 04:47 UT   22 52 31.0   -45 54 23    11.788   12.627  144.5    2.7   326   23.4 
2026-08-15 00:00 UT   22 52 07.8   -45 55 24    11.792   12.631  144.6    2.7   327   23.4 
2026-08-16 00:00 UT   22 51 38.6   -45 56 38    11.796   12.636  144.6    2.7   329   23.4 
2026-08-17 00:00 UT   22 51 09.3   -45 57 49    11.801   12.641  144.7    2.7   331   23.4 
2026-08-18 00:00 UT   22 50 39.8   -45 58 57    11.806   12.646  144.7    2.6   333   23.4 
2026-08-19 00:00 UT   22 50 10.2   -46 00 02    11.811   12.652  144.7    2.6   335   23.4 
2026-08-20 00:00 UT   22 49 40.5   -46 01 03    11.817   12.657  144.7    2.6   337   23.4 
2026-08-21 00:00 UT   22 49 10.7   -46 02 01    11.823   12.662  144.6    2.7   339   23.4 
2026-08-22 00:00 UT   22 48 40.9   -46 02 56    11.829   12.667  144.6    2.7   340   23.4 
2026-08-23 00:00 UT   22 48 10.9   -46 03 48    11.835   12.672  144.5    2.7   342   23.4 
2026-08-24 00:00 UT   22 47 40.9   -46 04 36    11.842   12.677  144.3    2.7   344   23.4 

    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.