The interactive map below shows our current prediction for the stellar occultation by (21900) Orus on 2021 October 16 UT. The prediction is based on a Gaia EDR3 position for the star, corrected for parallax and proper motion, and the v20210910200724 orbit estimate for Orus, which has a 1-sigma cross-track uncertainty of 6.9 km.
Geocentric mid-time of the event is 01:55:30 UT. Star position is RA 01:51:53.3, Dec +19:50:28 (J2000), and its magnitude is 11.77. Orus is moving at 16 km/s with respect to the star and its diameter is estimated to be 51 km, so central chords are expected to last 3.2 seconds. Orus' magnitude is predicted to be 16.6 at event time, so it will be 85 times fainter than the star.