C/2021 C5 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	11 Feb 2023	16.8	3.238 AU	3.419 AU	16h40m	-69°58'	71.2°	16.8°	260°
Nearest approach	20 Jun 2023	16.6	3.464 AU	2.800 AU	20h10m	-77°50'	123.3°	14.2°	322°
Today	9 May 2026	24.1	10.051 AU	10.409 AU	22h33m	+08°20'	66.6°	5.3°	255°

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. (9.0 + 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/2021 C5 (PANSTARRS) are:

    e (Eccentricity)                : 0.9980830
    q (Perihelion distance)         : 3.2380660
    i (Inclination)                 : 50.80920
    Ω (Longitude of ascending node) : 323.67600
    ω (Argument of perihelion)      : 270.85700
    L (Longitude of perihelion)     : 235.03206
    B (Latitude of perihelion)      : -50.80134
    T (Time of perihelion passage)  : 2459986.57230
    P (Orbital period in years)     : 69421.72

    Epoch                           : 2026 May 09
    Reference                       : MPEC 2026-E44

    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
2026-05-08 00:00 UT   22 33 32.6   +08 13 22    10.424   10.039   64.9    5.2   255   24.1 
2026-05-09 00:00 UT   22 33 41.0   +08 16 55    10.416   10.045   65.8    5.3   255   24.1 
2026-05-09 21:15 UT   22 33 48.2   +08 20 03    10.409   10.051   66.6    5.3   255   24.1 
2026-05-10 00:00 UT   22 33 49.2   +08 20 27    10.408   10.052   66.7    5.3   255   24.1 
2026-05-11 00:00 UT   22 33 56.9   +08 23 58    10.400   10.058   67.6    5.3   254   24.1 
2026-05-12 00:00 UT   22 34 04.4   +08 27 28    10.391   10.064   68.4    5.4   254   24.1 
2026-05-13 00:00 UT   22 34 11.5   +08 30 56    10.383   10.071   69.3    5.4   254   24.1 
2026-05-14 00:00 UT   22 34 18.3   +08 34 24    10.374   10.077   70.2    5.4   253   24.1 
2026-05-15 00:00 UT   22 34 24.8   +08 37 50    10.365   10.083   71.1    5.4   253   24.1 
2026-05-16 00:00 UT   22 34 30.9   +08 41 15    10.356   10.089   72.0    5.5   253   24.1 
2026-05-17 00:00 UT   22 34 36.7   +08 44 39    10.347   10.096   72.8    5.5   253   24.1 
2026-05-18 00:00 UT   22 34 42.1   +08 48 01    10.338   10.102   73.7    5.5   252   24.1 
2026-05-19 00:00 UT   22 34 47.2   +08 51 22    10.329   10.108   74.6    5.5   252   24.1 

    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.