The interactive map below shows our current prediction for the stellar occulation by (21900) Orus on 2019 September 7 UT. The prediction is based on a Gaia DR2 position for the star and the v20181128183142 orbit estimate for Orus.
Geocentric mid-time of the event is 21:54:47 UT. Star position is RA 21:15:24.8, Dec -06:04:11 (J2000), and its magnitude is 11.68. Orus is moving at 14 km/s with respect to the star and its diameter is estimated to be 62 km, so central chords are expected to last 4.4 seconds.