C/2020 F8 (SWAN) - DISINTEGRATED
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Disintegration	2 May 2020	5.2	0.728 AU	0.687 AU	00h04m	-11°24'	46.3°	90.8°	235°
Nearest approach	10 May 2020	5.6	0.573 AU	0.566 AU	01h15m	+17°04'	27.7°	124.9°	264°
Perihelion	25 May 2020	7.4	0.433 AU	0.907 AU	04h19m	+46°18'	25.3°	91.1°	5°
Today	9 Aug 2025	-	16.468 AU	16.634 AU	04h35m	-23°19'	78.8°	3.5°	247°

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 F8 (SWAN) are:

            e (Eccentricity)                : 1.0000620
            q (Perihelion distance)         : 0.4329220
            i (Inclination)                 : 110.55680
            Ω (Longitude of ascending node) : 259.80320
            ω (Argument of perihelion)      : 68.11530
            L (Longitude of perihelion)     : 218.64480
            B (Latitude of perihelion)      : 60.32517
            T (Time of perihelion passage)  : 2458995.24950

            Epoch                           : 2025 Aug 08
            Reference                       : MPEC 2023-J29

            Classification(s):              : Nearly isotropic; New (a > 10000 AU)
        

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 (10.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 7.74 + 5 log[∆] + 12.21 log[r]). The additional green curve shows the effect of forward scattering, occurring when the comet is between the earth and the sun, for a gas-to-dust light ratio δ90 of 0.30. (See Marcus 2007)

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
2025-08-09 00:00 UT   04 35 49.1   -23 19 27    16.635   16.467   78.7    3.5   247   28.7 
2025-08-09 04:42 UT   04 35 50.2   -23 19 55    16.634   16.468   78.8    3.5   247   28.7 
2025-08-10 00:00 UT   04 35 54.5   -23 21 50    16.629   16.473   79.4    3.5   248   28.7 
2025-08-11 00:00 UT   04 35 59.7   -23 24 14    16.623   16.479   80.0    3.5   248   28.7 
2025-08-12 00:00 UT   04 36 04.7   -23 26 39    16.617   16.485   80.7    3.5   249   28.7 
2025-08-13 00:00 UT   04 36 09.5   -23 29 06    16.611   16.490   81.4    3.5   250   28.7 
2025-08-14 00:00 UT   04 36 14.0   -23 31 34    16.605   16.496   82.0    3.5   250   28.7 
2025-08-15 00:00 UT   04 36 18.3   -23 34 03    16.599   16.502   82.7    3.5   251   28.7 
2025-08-16 00:00 UT   04 36 22.3   -23 36 34    16.594   16.508   83.4    3.5   252   28.7 
2025-08-17 00:00 UT   04 36 26.1   -23 39 06    16.588   16.514   84.1    3.5   252   28.7 
2025-08-18 00:00 UT   04 36 29.7   -23 41 39    16.581   16.520   84.7    3.5   253   28.7 
2025-08-19 00:00 UT   04 36 33.0   -23 44 13    16.575   16.526   85.4    3.5   254   28.7 

    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.