C/2021 J1 (Maury-Attard)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	19 Feb 2021	19.7	1.734 AU	2.324 AU	19h27m	+02°11'	42.8°	22.8°	289°
Nearest approach	27 May 2021	19.3	2.112 AU	1.301 AU	19h34m	-52°30'	131.3°	21.1°	290°
Today	4 Jul 2025	32.1	12.580 AU	12.948 AU	06h16m	-43°16'	66.7°	4.3°	189°

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 J1 (Maury-Attard) are:

            e (Eccentricity)                : 0.9338120
            q (Perihelion distance)         : 1.7338360
            i (Inclination)                 : 92.70760
            Ω (Longitude of ascending node) : 88.43230
            ω (Argument of perihelion)      : 147.19710
            L (Longitude of perihelion)     : 90.17623
            B (Latitude of perihelion)      : 32.76168
            T (Time of perihelion passage)  : 2459264.92490
            P (Orbital period in years)     : 134.07

            Epoch                           : 2025 Jul 03
            Reference                       : MPEC 2022-C56

            Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); Halley type (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. (15.50 + 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
2025-07-04 00:00 UT   06 16 04.2   -43 16 52    12.947   12.580   66.7    4.3   189   32.1 
2025-07-04 00:52 UT   06 16 05.1   -43 16 52    12.948   12.580   66.7    4.3   189   32.1 
2025-07-05 00:00 UT   06 16 28.1   -43 16 59    12.952   12.586   66.7    4.3   190   32.1 
2025-07-06 00:00 UT   06 16 52.0   -43 17 10    12.957   12.591   66.7    4.3   191   32.1 
2025-07-07 00:00 UT   06 17 15.8   -43 17 25    12.962   12.597   66.8    4.3   192   32.1 
2025-07-08 00:00 UT   06 17 39.4   -43 17 43    12.967   12.602   66.8    4.3   193   32.1 
2025-07-09 00:00 UT   06 18 03.0   -43 18 05    12.972   12.607   66.9    4.3   194   32.1 
2025-07-10 00:00 UT   06 18 26.5   -43 18 31    12.976   12.613   66.9    4.3   195   32.1 
2025-07-11 00:00 UT   06 18 49.9   -43 19 01    12.981   12.618   67.0    4.3   196   32.1 
2025-07-12 00:00 UT   06 19 13.1   -43 19 34    12.985   12.624   67.0    4.3   196   32.1 
2025-07-13 00:00 UT   06 19 36.3   -43 20 11    12.989   12.629   67.1    4.3   197   32.1 
2025-07-14 00:00 UT   06 19 59.3   -43 20 52    12.993   12.635   67.2    4.3   198   32.1 

    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.