News On This Day In History: Supernova Observed In The Constellation Cassiopeia Was Recorded – On August 4, 1181 AncientPages.com | August 4, 2016 AncentPages.com - On August 4, 1181, a supernova was observed in the constellation Cassiopeia. Chinese and Japanese astronomers observed this supernova on August 4 and then on August Read More