C/2020 F8 (SWAN) - DISINTEGRATED
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Disintegration	2 May 2020	5.2	0.716 AU	0.677 AU	00h05m	-09°37'	45.2°	92.6°	237°
Nearest approach	10 May 2020	5.5	0.572 AU	0.571 AU	01h12m	+17°18'	28.0°	124.1°	265°
Perihelion	25 May 2020	7.3	0.435 AU	0.906 AU	04h15m	+46°20'	25.4°	91.1°	4°
Today	8 Sep 2026	-	18.709 AU	18.515 AU	04h33m	-25°44'	99.5°	3.0°	268°

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 7.8 + 5 log[∆] + 12.2 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 F8 (SWAN) are:

    e (Eccentricity)                : 0.9997760
    q (Perihelion distance)         : 0.4351460
    i (Inclination)                 : 110.60310
    Ω (Longitude of ascending node) : 259.85970
    ω (Argument of perihelion)      : 68.18590
    L (Longitude of perihelion)     : 218.53886
    B (Latitude of perihelion)      : 60.34435
    T (Time of perihelion passage)  : 2458994.56190
    P (Orbital period in years)     : 85621.03

    Epoch                           : 2026 May 29
    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
2026-09-07 00:00 UT   04 33 48.6   -25 41 59    18.520   18.703   98.9    3.1   267   29.6 
2026-09-08 00:00 UT   04 33 46.9   -25 44 30    18.515   18.708   99.5    3.0   268   29.6 
2026-09-08 00:26 UT   04 33 46.8   -25 44 32    18.515   18.709   99.5    3.0   268   29.6 
2026-09-09 00:00 UT   04 33 44.9   -25 47 01    18.509   18.714  100.2    3.0   269   29.6 
2026-09-10 00:00 UT   04 33 42.7   -25 49 33    18.503   18.720  100.8    3.0   269   29.6 
2026-09-11 00:00 UT   04 33 40.3   -25 52 04    18.498   18.725  101.5    3.0   270   29.6 
2026-09-12 00:00 UT   04 33 37.6   -25 54 36    18.492   18.731  102.2    3.0   271   29.6 
2026-09-13 00:00 UT   04 33 34.7   -25 57 08    18.487   18.736  102.8    3.0   272   29.6 
2026-09-14 00:00 UT   04 33 31.6   -25 59 39    18.481   18.742  103.5    3.0   273   29.6 
2026-09-15 00:00 UT   04 33 28.2   -26 02 11    18.476   18.747  104.1    3.0   273   29.6 
2026-09-16 00:00 UT   04 33 24.6   -26 04 42    18.471   18.753  104.7    3.0   274   29.6 
2026-09-17 00:00 UT   04 33 20.7   -26 07 14    18.466   18.758  105.4    3.0   275   29.6 
2026-09-18 00:00 UT   04 33 16.6   -26 09 45    18.461   18.764  106.0    3.0   276   29.6 

    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.