The interactive map below shows our current prediction for the stellar occultation by (21900) Orus on 2021 August 13 UT. The prediction is based on a Gaia DR2 position for the star, corrected for parallax and proper motion, and the v20200901193809 orbit estimate for Orus, which has a 1-sigma cross-track uncertainty of 15.7 km.
Geocentric mid-time of the event is 02:55:31 UT. Star position is RA 02:07:01.5, Dec +20:36:56 (J2000), and its magnitude is 16.88. Orus is moving at 6 km/s with respect to the star and its diameter is estimated to be 51 km, so central chords are expected to last 8.1 seconds.