C/2020 F5 (MASTER)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Mar 2021	15.2	4.325 AU	4.994 AU	22h37m	-42°43'	43.3°	9.1°	204°
Nearest approach	22 Aug 2021	14.7	4.514 AU	3.586 AU	23h14m	-32°48'	153.6°	5.7°	319°
Today	15 Dec 2025	21.5	12.749 AU	12.277 AU	00h25m	+53°48'	116.6°	4.0°	86°

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 5.9 + 5 log[∆] + 9.2 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 F5 (MASTER) are:

    e (Eccentricity)                : 0.9733940
    q (Perihelion distance)         : 4.3248870
    i (Inclination)                 : 52.24100
    Ω (Longitude of ascending node) : 350.56000
    ω (Argument of perihelion)      : 310.58210
    L (Longitude of perihelion)     : 314.99967
    B (Latitude of perihelion)      : -36.90110
    T (Time of perihelion passage)  : 2459289.42750
    P (Orbital period in years)     : 2072.49

    Epoch                           : 2025 Dec 14
    Reference                       : MPEC 2024-UQ8

    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
2025-12-14 00:00 UT   00 25 54.7   +53 52 37    12.258   12.742  117.5    3.9    88   21.5 
2025-12-15 00:00 UT   00 25 50.4   +53 49 40    12.272   12.748  116.8    4.0    87   21.5 
2025-12-15 07:46 UT   00 25 49.1   +53 48 43    12.277   12.749  116.6    4.0    86   21.5 
2025-12-16 00:00 UT   00 25 46.6   +53 46 44    12.287   12.753  116.2    4.0    86   21.5 
2025-12-17 00:00 UT   00 25 43.3   +53 43 48    12.302   12.758  115.6    4.0    85   21.5 
2025-12-18 00:00 UT   00 25 40.6   +53 40 54    12.317   12.764  115.0    4.0    84   21.5 
2025-12-19 00:00 UT   00 25 38.5   +53 37 60    12.332   12.769  114.3    4.0    83   21.5 
2025-12-20 00:00 UT   00 25 36.8   +53 35 07    12.348   12.775  113.7    4.0    82   21.5 
2025-12-21 00:00 UT   00 25 35.7   +53 32 15    12.363   12.780  113.0    4.1    81   21.5 
2025-12-22 00:00 UT   00 25 35.1   +53 29 25    12.378   12.785  112.4    4.1    80   21.5 
2025-12-23 00:00 UT   00 25 35.0   +53 26 36    12.394   12.791  111.7    4.1    80   21.5 
2025-12-24 00:00 UT   00 25 35.5   +53 23 48    12.410   12.796  111.0    4.1    79   21.5 
2025-12-25 00:00 UT   00 25 36.4   +53 21 01    12.426   12.802  110.4    4.1    78   21.5 

    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.