C/2020 H8 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	4 Jun 2020	20.2	4.661 AU	4.090 AU	17h43m	+37°45'	118.5°	11.0°	193°
Nearest approach	18 Jun 2020	20.2	4.662 AU	4.066 AU	17h23m	+36°00'	120.3°	10.8°	173°
Today	22 Dec 2025	27.9	14.329 AU	14.761 AU	13h14m	-70°51'	62.2°	3.5°	261°

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. The light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (10.5 + 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 H8 (PANSTARRS) are:

    e (Eccentricity)                : 0.9920480
    q (Perihelion distance)         : 4.6607560
    i (Inclination)                 : 99.69870
    Ω (Longitude of ascending node) : 68.43180
    ω (Argument of perihelion)      : 128.79280
    L (Longitude of perihelion)     : 80.26878
    B (Latitude of perihelion)      : 50.19939
    T (Time of perihelion passage)  : 2459005.37270
    P (Orbital period in years)     : 14189.59

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2021-N06

    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
2025-12-21 00:00 UT   13 14 20.5   -70 43 34    14.762   14.319   61.5    3.5   259   27.9 
2025-12-22 00:00 UT   13 14 27.0   -70 47 41    14.762   14.324   61.8    3.5   261   27.9 
2025-12-22 22:35 UT   13 14 32.4   -70 51 34    14.761   14.329   62.2    3.5   261   27.9 
2025-12-23 00:00 UT   13 14 32.7   -70 51 49    14.761   14.329   62.2    3.5   262   27.9 
2025-12-24 00:00 UT   13 14 37.7   -70 55 57    14.760   14.335   62.6    3.5   263   27.9 
2025-12-25 00:00 UT   13 14 41.9   -71 00 06    14.760   14.340   63.0    3.5   264   27.9 
2025-12-26 00:00 UT   13 14 45.4   -71 04 15    14.759   14.345   63.4    3.5   265   27.9 
2025-12-27 00:00 UT   13 14 48.1   -71 08 25    14.758   14.350   63.8    3.5   266   27.9 
2025-12-28 00:00 UT   13 14 50.1   -71 12 35    14.757   14.356   64.1    3.5   267   27.9 
2025-12-29 00:00 UT   13 14 51.3   -71 16 45    14.755   14.361   64.6    3.5   268   27.9 
2025-12-30 00:00 UT   13 14 51.6   -71 20 55    14.754   14.366   65.0    3.6   269   27.9 
2025-12-31 00:00 UT   13 14 51.2   -71 25 06    14.753   14.371   65.4    3.6   270   27.9 
2026-01-01 00:00 UT   13 14 50.0   -71 29 16    14.751   14.377   65.8    3.6   271   27.9 

    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.