This week, search out the constellation Cassiopeia. For northern hemisphere observers it is going to be high in the sky throughout the coming winter months. Indeed, for much of the northern hemisphere, it is a circumpolar constellation visible all year round.
For most southern hemisphere observers, the constellation is never visible. Only those in the southern tropics stand a chance of seeing the star pattern. It will appear low in the northern sky during this month.
The chart shows the view looking up towards the zenith from London. Cassiopeia is easily recognised as a W-shaped pattern of five stars.
In Greek mythology, she was the mother of Andromeda, and boasted that their familial beauty was greater than even the exquisite sea nymphs. Such hubris attracted the wrath of Poseidon, who was married to the eldest nymph Amphitrite.
Poseidon’s ultimate punishment was to place Cassiopeia in the stars, chained to her throne for all eternity. Hence the W-shape represents the queen in a seated position.
Cassiopeia is one of the original 48 constellations listed in the second century by Ptolemy. The constellation’s neighbours were also derived from the same myth: Andromeda, Pegasus, Perseus, Cetus and Cepheus.