ephemeris date magn radius delta ra dec elong phase PA
Perihelion5 Feb 201912.92.135 AU1.259 AU11h40m+30°26'143.7°15.9°255°
Nearest approach27 Feb 201912.92.142 AU1.207 AU11h28m+31°40'154.2°11.6°208°
Today5 Dec 202026.74.480 AU5.343 AU18h34m-33°57'26.2°5.6°109°
123P/West-Hartley- 2020-12-05

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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 123P/West-Hartley, as provided by the minor planet center, are:

            e (eccentricity)                : 0.4482410
            q (perihelion distance)         : 2.1350010
            i (inclination)                 : 15.31550
            Ω (Longitude of ascending node) : 46.34770
            ω (Argument of perihelion)      : 103.53320
            L (Longitude of perihelion)     : -29.64009
            B (Latitude of perihelion)      : 14.88028
            T (Time of perihelion passage)  : 2458520.10290
            P (Orbital period in years)     : 7.61
            Epoch                           : 2020 Dec 04

            Family/Group:                   : Jupiter family
            Tisserand (Jupiter)             : 2.832

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 (4.00 + 5 log[∆] + 25.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 1.55 + 5 log[∆] + 33.07 log[r]).