C/2020 F5 (MASTER)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	16 Mar 2021	15.2	4.326 AU	4.994 AU	22h38m	-42°42'	43.4°	9.1°	204°
Nearest approach	22 Aug 2021	14.7	4.515 AU	3.586 AU	23h13m	-32°48'	153.6°	5.7°	319°
Today	18 Sep 2025	21.2	12.275 AU	11.739 AU	00h57m	+56°12'	120.2°	4.1°	201°

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 F5 (MASTER) are:

            e (Eccentricity)                : 0.9735360
            q (Perihelion distance)         : 4.3257930
            i (Inclination)                 : 52.23640
            Ω (Longitude of ascending node) : 350.55000
            ω (Argument of perihelion)      : 310.60310
            L (Longitude of perihelion)     : 315.00697
            B (Latitude of perihelion)      : -36.88492
            T (Time of perihelion passage)  : 2459289.55650
            P (Orbital period in years)     : 2089.85

            Epoch                           : 2025 Sep 17
            Reference                       : MPEC 2024-UQ8

            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 (6.50 + 5 log[∆] + 8.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 5.88 + 5 log[∆] + 9.19 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
2025-09-18 00:00 UT   00 58 11.4   +56 11 60    11.741   12.271  119.8    4.1   202   21.2 
2025-09-18 17:06 UT   00 57 51.6   +56 12 46    11.739   12.275  120.2    4.1   201   21.2 
2025-09-19 00:00 UT   00 57 43.5   +56 13 04    11.738   12.276  120.3    4.1   201   21.2 
2025-09-20 00:00 UT   00 57 15.4   +56 14 03    11.735   12.282  120.9    4.0   200   21.2 
2025-09-21 00:00 UT   00 56 47.1   +56 14 58    11.733   12.287  121.4    4.0   199   21.2 
2025-09-22 00:00 UT   00 56 18.5   +56 15 49    11.731   12.293  122.0    4.0   198   21.2 
2025-09-23 00:00 UT   00 55 49.8   +56 16 35    11.729   12.298  122.5    3.9   197   21.2 
2025-09-24 00:00 UT   00 55 20.9   +56 17 16    11.727   12.304  123.1    3.9   196   21.2 
2025-09-25 00:00 UT   00 54 51.8   +56 17 53    11.725   12.309  123.6    3.9   194   21.2 
2025-09-26 00:00 UT   00 54 22.6   +56 18 25    11.724   12.314  124.1    3.9   193   21.2 
2025-09-27 00:00 UT   00 53 53.2   +56 18 53    11.723   12.320  124.6    3.8   192   21.2 
2025-09-28 00:00 UT   00 53 23.7   +56 19 16    11.721   12.325  125.1    3.8   191   21.2 

    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.