The interactive map below shows our current prediction for the occultation by (617) Patroclus-Menoetius on 2023 September 22 UT. The prediction is based on a Gaia eDR3 position for the star, corrected for parallax and proper motion, and the v20230508150910 orbit estimate for Patroclus-Menoetius, which is derived from patroclus_20220708a_5occ1.bsp (barycenter) and pm5_ccloud1.bsp (mutual orbit). This ephemeris has a 1-sigma crosstrack uncertainty of 10.0 km and a 1-sigma downtrack uncertainty of 0.1 sec for this event (these are placeholder values).
The geocentric mid-time of the event is 13:31:27.6 UT. The J2000 star position is RA 21:39:25.1 (21.6569600), Dec -41:40:21 (-41.672404), and its magnitude is 11.68. Patroclus and Menoetius are moving at 10.8 km/s with respect to the star and their diameters are estimated to be 113 and 108 km, respectively, so central chords are expected to last 10.5 seconds for Patroclus and 10.0 seconds for Menoetius.
Of-date coordinates for the target star on event night are RA 21:40:54.1 (21.6816944), Dec -41:33:51 (-41.564167).