C/2021 O3 (PANSTARRS) - DISINTEGRATED
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Disintegration	21 Apr 2022	9.4	0.285 AU	0.974 AU	02h51m	+03°15'	16.5°	87.9°	121°
Perihelion	21 Apr 2022	-	0.285 AU	0.963 AU	02h52m	+03°32'	16.5°	90.1°	121°
Nearest approach	8 May 2022	11.9	0.591 AU	0.604 AU	03h59m	+46°50'	32.0°	115.2°	27°
Today	21 May 2025	-	11.633 AU	11.381 AU	19h39m	+36°36'	101.9°	4.9°	233°

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.)

The orbital elements of C/2021 O3 (PANSTARRS) are:

            e (Eccentricity)                : 1.0000510
            q (Perihelion distance)         : 0.2851600
            i (Inclination)                 : 56.82510
            Ω (Longitude of ascending node) : 188.80240
            ω (Argument of perihelion)      : 300.01300
            L (Longitude of perihelion)     : 145.35335
            B (Latitude of perihelion)      : -46.44987
            T (Time of perihelion passage)  : 2459690.77130

            Epoch                           : 2025 May 19
            Reference                       : MPEC 2022-L66

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (10.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 12.59 + 5 log[∆] + 5.68 log[r]). The additional green curve shows the effect of forward scattering, occurring when the comet is between the earth and the sun, for a gas-to-dust light ratio δ90 of 0.30. (See Marcus 2007)

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-05-21 00:00 UT   19 39 35.5   +36 35 17    11.382   11.630  101.7    4.9   234   23.9 
2025-05-21 10:04 UT   19 39 29.6   +36 36 35    11.381   11.633  101.9    4.9   233   23.9 
2025-05-22 00:00 UT   19 39 21.4   +36 38 22    11.380   11.637  102.2    4.9   233   23.9 
2025-05-23 00:00 UT   19 39 06.9   +36 41 24    11.378   11.644  102.7    4.9   232   23.9 
2025-05-24 00:00 UT   19 38 52.1   +36 44 22    11.377   11.651  103.2    4.9   231   23.9 
2025-05-25 00:00 UT   19 38 36.9   +36 47 17    11.376   11.658  103.7    4.8   230   23.9 
2025-05-26 00:00 UT   19 38 21.4   +36 50 09    11.375   11.665  104.2    4.8   229   23.9 
2025-05-27 00:00 UT   19 38 05.5   +36 52 58    11.373   11.672  104.7    4.8   228   23.9 
2025-05-28 00:00 UT   19 37 49.3   +36 55 43    11.372   11.679  105.2    4.8   227   23.9 
2025-05-29 00:00 UT   19 37 32.7   +36 58 24    11.371   11.686  105.7    4.8   226   23.9 
2025-05-30 00:00 UT   19 37 15.8   +37 01 02    11.370   11.693  106.1    4.8   226   23.9 
2025-05-31 00:00 UT   19 36 58.6   +37 03 36    11.370   11.700  106.6    4.8   225   23.9 

    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.