C/2021 C4 (ATLAS)
ephemeris date magn radius delta ra dec elong phase PA
Perihelion18 Jan 202119.04.507 AU4.834 AU15h02m-44°12'65.0°11.4°275°
Today11 Apr 202118.44.557 AU3.656 AU13h40m-37°21'150.7°6.2°350°
Nearest approach21 Apr 202118.44.570 AU3.633 AU13h24m-34°44'156.0°5.1°21°
C/2021 C4 (ATLAS)- 2021-04-11

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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 C4 (ATLAS), as provided by the minor planet center, are:

            e (eccentricity)                : 1.0022800
            q (perihelion distance)         : 4.5066410
            i (inclination)                 : 132.86530
            Ω (Longitude of ascending node) : 194.25880
            ω (Argument of perihelion)      : 320.40430
            L (Longitude of perihelion)     : 223.62474
            B (Latitude of perihelion)      : -27.85015
            T (Time of perihelion passage)  : 2459232.85270

            Epoch                           : 2021 Apr 10
            Reference                       : MPEC 2021-FB5

            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 light curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the minor planet center. (9.00 + 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.