May 1: Supernova!

Over the night of April 30/May 1, 1006, Supernova SN1006 appeared. This was the brightest stellar phenomenon in recorded history, with an apparent radius about half that of the full moon. Reported worldwide, the nova was visible through the daytime and sufficient to read by at night. Astrologers viewed it as a portent of war, famine, and cataclysm. Remaining at its greatest magnitude for about three months, the nova faded over the following 18.