The interactive map below shows our current prediction for the stellar occulation by (52246) Donaldjohanson on 2019 July 27 UT. The prediction is based on a Gaia DR2 position for the star and the v20181128190018 orbit estimate for Donaldjohanson.
Geocentric mid-time of the event is 12:32:36 UT. Star position is RA 20:38:02.3, Dec -13:32:12 (J2000), and its magnitude is 13.67. Donaldjohanson is moving at 13 km/s with respect to the star and its diameter is estimated to be 5 km, so central chords are expected to last 0.38 seconds.