A/2021 E2
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	9 Dec 2020	21.5	2.283 AU	3.011 AU	14h37m	-18°21'	35.5°	14.5°	284°
Nearest approach	9 Mar 2021	19.8	2.493 AU	1.514 AU	12h06m	+05°30'	167.8°	4.8°	266°
Today	20 Apr 2024	27.3	10.708 AU	11.340 AU	05h04m	+34°06'	48.9°	4.1°	75°

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 A/2021 E2 are:

            e (Eccentricity)                : 0.9892800
            q (Perihelion distance)         : 2.2828670
            i (Inclination)                 : 167.48950
            Ω (Longitude of ascending node) : 190.80030
            ω (Argument of perihelion)      : 342.30840
            L (Longitude of perihelion)     : 208.09717
            B (Latitude of perihelion)      : -3.77445
            T (Time of perihelion passage)  : 2459193.47610
            P (Orbital period in years)     : 3107.63

            Epoch                           : 2024 Apr 19
            Reference                       : MPEC 2022-UY9

            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 gray curve indicates the expected brightness if this object is a comet (15.00 + 5 log[∆] + 5.00 log[r]), whereas the red curve indicates the expected lightcurve for an asteroid (H=16.50; G=.15).

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
2024-04-20 00:00 UT   05 04 48.3   +34 06 43    11.333   10.705   49.3    4.1    75   27.3 
2024-04-20 08:48 UT   05 04 52.9   +34 06 30    11.340   10.708   48.9    4.1    75   27.3 
2024-04-21 00:00 UT   05 05 00.8   +34 06 09    11.353   10.712   48.4    4.0    74   27.3 
2024-04-22 00:00 UT   05 05 13.6   +34 05 35    11.372   10.718   47.5    4.0    74   27.3 
2024-04-23 00:00 UT   05 05 26.7   +34 05 03    11.391   10.725   46.6    3.9    74   27.3 
2024-04-24 00:00 UT   05 05 40.0   +34 04 32    11.409   10.731   45.7    3.8    73   27.3 
2024-04-25 00:00 UT   05 05 53.5   +34 04 02    11.428   10.738   44.8    3.8    73   27.3 
2024-04-26 00:00 UT   05 06 07.3   +34 03 33    11.446   10.744   43.9    3.7    73   27.3 
2024-04-27 00:00 UT   05 06 21.3   +34 03 06    11.465   10.751   43.0    3.7    72   27.3 
2024-04-28 00:00 UT   05 06 35.5   +34 02 39    11.483   10.757   42.1    3.6    72   27.3 
2024-04-29 00:00 UT   05 06 50.0   +34 02 13    11.500   10.764   41.2    3.5    72   27.3 
2024-04-30 00:00 UT   05 07 04.6   +34 01 48    11.518   10.770   40.4    3.5    71   27.3 

    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.