The interactive map below shows our current prediction for the stellar occultation by (21900) Orus on 2019 September 7 UT. The prediction is based on a Gaia DR2 position for the star and the v20190830184858 orbit estimate for Orus.
Geocentric mid-time of the event is 21:54:38 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 51 km, so central chords are expected to last 3.7 seconds. Orus' magnitude is predicted to be 17.5 at event time, so it will be 200 times fainter than the star.