It can't get much better than this: an occultation of the brightest star the Moon ever crosses, visible across most of the U.S. on a Saturday evening, with the Moon barely first-quarter (46% sunlit), and the star's dark-side disappearance visible without optical aid.
Moreover, along a narrow path skirting the U.S.-Canadian border, passing the Toronto area and then the U.S. Northeast, a spectacular grazing occultation will occur that, at least in the populous eastern part of the path, will be nearly as good as last July's well-observed Aldebaran graze in the southern plains.
The graze provides another opportunity to detect the angular size of a star other than the Sun. But this time, the Moon will be brighter with the graze events occurring closer to the northern cusp, so binoculars are recommended to see the gradual and partial occultation events that will reveal the star's angular size.
The occultation will also be visible at night throughout Mexico, most of Central America, the western Caribbean Sea, and Bermuda. The occultation will occur in daylight in Hawai'i (disappearance at 3:33 p.m. HST in Honolulu).
The southern-limit graze will occur on the Moon's sunlit limb 6° inside the southern cusp, as seen from a narrow path crossing Costa Rica, Panama, and Colombia. A telescope is needed to see or record the star's reappearance even at night, because this will occur on the Moon's sunlit edge.
