On 2018 Apr 06, 04:33 UT, the 31.6 km diameter asteroid (3641) Williams Bay will occult the 8.4 mag star HD 113227 in the constellation Virgo for observers along a path across N USA, S Canada.
Asteroid (3641) Williams Bay (A922 WC) is a main belt asteroid that orbits the Sun over 5.17 years at an average distance of 2.99 AU. The asteroid was discovered by Belgian astronomer George Van Biesbroeck at the Yerkes Observatory in Williams Bay, Wisconsin, on the 24th November 1922. The name of the asteroid is derived from the site of the observatory where the asteroid was discovered.