November 11th 923 Arab astronomers observe eclipse of the Sun
The Arab astronomer Abu al Hassan Ali ibn Amajur observed a total solar eclipse of the Sun from modern day Iraq. This eclipse was not visible in Britain.
November 11th 1572 Tycho Brahe observes Supernova in Cassiopeia.
The Danish astronomer Tycho Brahe the last of the great pre- telescopic astronomers first observed the bright star in the constellation of Cassiopeia. Today we now know it was a supernova. This is a star that destroys itself in a massive explosion. Although he was not the first to see it Tycho observed it continuously until it faded from view, hence its name today is Tycho's Star. Astronomers refer to it as Supernova SN1572.