This message is forwarded from David Dunham of the International Occultation Timing Association (IOTA).
Around 1 a.m. CDT (2 a.m. EDT) on the night of Saturday-Sunday, July 18-19, the moderately large asteroid 790 Pretoria occults a 10th-magnitude star in Pegasus for observers in a wide swath of land from Florida through Minnesota and past Winnipeg. The 3.5-magnitude drop in brightness may last up to 16 seconds and should be visible through a 4-inch or larger telescope.
IOTA is campaigning to have this event well covered by observers doing accurate timings, preferably by video recording. If you want to provide scientifically valuable observations, please read the information at iota.jhuapl.edu/timng920.htm and consider downloading the free book Chasing the Shadow: The IOTA Occultation Observer's Manual.