C/2020 K4 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	5 Mar 2020	20.9	1.742 AU	2.434 AU	22h08m	-40°29'	36.7°	19.9°	204°
Nearest approach	7 Jun 2020	20.0	2.092 AU	1.101 AU	18h15m	-26°21'	163.0°	8.2°	278°
Today	22 Dec 2025	34.2	15.111 AU	14.983 AU	13h30m	+51°48'	95.6°	3.7°	301°

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 16.6 + 5 log[∆] + 10.0 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 K4 (PANSTARRS) are:

    e (Eccentricity)                : 0.9271400
    q (Perihelion distance)         : 1.7418350
    i (Inclination)                 : 125.58530
    Ω (Longitude of ascending node) : 264.27030
    ω (Argument of perihelion)      : 308.75360
    L (Longitude of perihelion)     : 300.21079
    B (Latitude of perihelion)      : -39.36135
    T (Time of perihelion passage)  : 2458913.62860
    P (Orbital period in years)     : 116.89

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2020-L06

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); Halley type (P < 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-21 00:00 UT   13 30 36.7   +51 44 22    14.990   15.105   94.8    3.7   303   34.2 
2025-12-22 00:00 UT   13 30 43.9   +51 47 35    14.985   15.110   95.4    3.7   302   34.2 
2025-12-22 07:46 UT   13 30 46.2   +51 48 38    14.983   15.111   95.6    3.7   301   34.2 
2025-12-23 00:00 UT   13 30 50.8   +51 50 50    14.980   15.114   96.0    3.7   301   34.2 
2025-12-24 00:00 UT   13 30 57.3   +51 54 08    14.974   15.119   96.6    3.7   300   34.2 
2025-12-25 00:00 UT   13 31 03.4   +51 57 28    14.969   15.124   97.2    3.7   299   34.2 
2025-12-26 00:00 UT   13 31 09.2   +52 00 50    14.964   15.128   97.8    3.7   298   34.2 
2025-12-27 00:00 UT   13 31 14.5   +52 04 15    14.959   15.133   98.3    3.7   298   34.2 
2025-12-28 00:00 UT   13 31 19.5   +52 07 41    14.954   15.138   98.9    3.7   297   34.2 
2025-12-29 00:00 UT   13 31 24.1   +52 11 09    14.949   15.143   99.5    3.7   296   34.2 
2025-12-30 00:00 UT   13 31 28.3   +52 14 39    14.944   15.147  100.1    3.7   295   34.2 
2025-12-31 00:00 UT   13 31 32.1   +52 18 11    14.939   15.152  100.7    3.7   294   34.2 
2026-01-01 00:00 UT   13 31 35.5   +52 21 45    14.934   15.157  101.3    3.6   293   34.2 

    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.