ephemeris date magn radius delta ra dec elong phase PA
Today22 Oct 201814.82.282 AU2.357 AU09h29m+28°54'73.4°24.7°293°
Perihelion5 Feb 201912.72.127 AU1.253 AU11h40m+30°39'143.4°16.1°255°
Nearest approach28 Feb 201912.62.135 AU1.200 AU11h27m+31°57'154.0°11.7°207°
123P/West-Hartley - 2018-10-22

-1 month
-1 week
-1 day
+1 day
+1 week
+1 month

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)                : 0.448715
            q (perihelion distance)         : 2.126891
            i (inclination)                 : 15.3596
            Ω (Longitude of ascending node) : 46.5000
            ω (Argument of perihelion)      : 103.0039
            L (Longitude of perihelion)     : -30.0317
            B (Latitude of perihelion)      : 14.9564
            T (Time of perihelion passage)  : 2458519.5970
            P (Orbital period in years)     : 7.58

            Family/Group:                   : Jupiter family

The lightcurve 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 lightcurve is based on the absolute magnitide and slope parameter as provided the minor planet center (4.00 + 5 log[∆] + 25.00 log[r]).

The all-sky chart below shows the path of of the comet over the same period as the lightcurve. The comet's current position is marked yellow.

The following chart show the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.
A more printer-friendly versions of the same chart can be found further down this page as well.