C/2020 F8 (SWAN) - DISINTEGRATED
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Disintegration	2 May 2020	5.2	0.724 AU	0.683 AU	00h04m	-10°47'	45.9°	91.4°	236°
Nearest approach	10 May 2020	5.4	0.573 AU	0.568 AU	01h14m	+17°09'	27.8°	124.6°	264°
Perihelion	25 May 2020	7.4	0.434 AU	0.907 AU	04h18m	+46°18'	25.3°	91.1°	5°
Today	21 Jan 2026	-	17.435 AU	17.164 AU	04h09m	-26°48'	104.4°	3.1°	59°

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)                : 1.0000510
    q (Perihelion distance)         : 0.4336680
    i (Inclination)                 : 110.56660
    Ω (Longitude of ascending node) : 259.81540
    ω (Argument of perihelion)      : 68.13380
    L (Longitude of perihelion)     : 218.61754
    B (Latitude of perihelion)      : 60.33176
    T (Time of perihelion passage)  : 2458995.00460

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2023-J29

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-01-20 00:00 UT   04 09 36.0   -26 52 13    17.131   17.424  105.7    3.1    57   29.0 
2026-01-21 00:00 UT   04 09 27.2   -26 50 27    17.148   17.430  105.0    3.1    58   29.0 
2026-01-21 22:48 UT   04 09 19.1   -26 48 46    17.164   17.435  104.4    3.1    59   29.0 
2026-01-22 00:00 UT   04 09 18.7   -26 48 40    17.165   17.436  104.3    3.1    59   29.0 
2026-01-23 00:00 UT   04 09 10.4   -26 46 52    17.182   17.441  103.7    3.1    59   29.0 
2026-01-24 00:00 UT   04 09 02.4   -26 45 01    17.199   17.447  103.0    3.2    60   29.0 
2026-01-25 00:00 UT   04 08 54.6   -26 43 09    17.216   17.453  102.3    3.2    61   29.0 
2026-01-26 00:00 UT   04 08 47.1   -26 41 16    17.234   17.459  101.6    3.2    62   29.1 
2026-01-27 00:00 UT   04 08 39.8   -26 39 21    17.251   17.464  100.9    3.2    63   29.1 
2026-01-28 00:00 UT   04 08 32.8   -26 37 25    17.268   17.470  100.2    3.2    63   29.1 
2026-01-29 00:00 UT   04 08 26.1   -26 35 27    17.286   17.476   99.5    3.2    64   29.1 
2026-01-30 00:00 UT   04 08 19.6   -26 33 28    17.303   17.482   98.8    3.2    65   29.1 
2026-01-31 00:00 UT   04 08 13.3   -26 31 28    17.320   17.487   98.1    3.2    66   29.1 

    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.