C/2021 B2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	15 Dec 2020	20.5	2.925 AU	2.312 AU	03h30m	-29°40'	119.6°	17.0°	32°
Perihelion	4 May 2021	20.5	2.513 AU	3.172 AU	05h38m	+11°27'	41.9°	15.5°	101°
Today	6 Jan 2025	29.9	11.355 AU	11.735 AU	15h40m	+17°39'	65.0°	4.5°	306°

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 B2 (PANSTARRS) are:

            e (Eccentricity)                : 0.9936870
            q (Perihelion distance)         : 2.5131630
            i (Inclination)                 : 38.08500
            Ω (Longitude of ascending node) : 120.45540
            ω (Argument of perihelion)      : 335.07510
            L (Longitude of perihelion)     : 100.36420
            B (Latitude of perihelion)      : -15.06713
            T (Time of perihelion passage)  : 2459339.29740
            P (Orbital period in years)     : 7942.87

            Epoch                           : 2025 Jan 05
            Reference                       : MPEC 2022-L66

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

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 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. (14.00 + 5 log[∆] + 10.00 log[r]).

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
2025-01-06 00:00 UT   15 40 09.0   +17 38 43    11.737   11.352   64.7    4.5   307   29.9 
2025-01-06 11:35 UT   15 40 17.3   +17 39 22    11.735   11.355   65.0    4.5   306   29.9 
2025-01-07 00:00 UT   15 40 26.1   +17 40 04    11.732   11.358   65.4    4.5   306   29.9 
2025-01-08 00:00 UT   15 40 42.9   +17 41 28    11.726   11.365   66.2    4.5   305   29.9 
2025-01-09 00:00 UT   15 40 59.4   +17 42 55    11.720   11.371   66.9    4.6   304   29.9 
2025-01-10 00:00 UT   15 41 15.6   +17 44 25    11.715   11.377   67.6    4.6   304   29.9 
2025-01-11 00:00 UT   15 41 31.6   +17 45 58    11.709   11.384   68.4    4.6   303   29.9 
2025-01-12 00:00 UT   15 41 47.4   +17 47 33    11.703   11.390   69.1    4.6   303   29.9 
2025-01-13 00:00 UT   15 42 02.8   +17 49 11    11.696   11.396   69.9    4.6   302   29.9 
2025-01-14 00:00 UT   15 42 18.0   +17 50 51    11.690   11.402   70.6    4.7   301   29.9 
2025-01-15 00:00 UT   15 42 32.8   +17 52 35    11.684   11.409   71.4    4.7   301   29.9 
2025-01-16 00:00 UT   15 42 47.4   +17 54 21    11.678   11.415   72.2    4.7   300   29.9 

    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.