Five of the stars of Cassiopeia form a W shape, which is one of the most distinctive patterns in the northern sky.
Cassiopeia was the site of Tycho Brahe's supernova of 1572, and is also the location of Cassiopeia A, the strongest radio source in the sky (other than the sun). Cassiopeia A is the remnant of a supernova which apparently occurred in about 1667, although there is no record of it having been observed.