This week, stargazers have an opportunity to track down the constellation Cetus, also known as the whale or sea monster. Despite being one of the faintest constellations, it sprawls across a vast area of the sky, covering roughly 1,230 square degrees, making it the fourth largest of the 88 modern constellations. Its lack of bright stars gives it a hypnotic quality as observers trace its faint outline.
The chart shows the view looking south-southeast from London on 17 November at 20:00 GMT, though the view remains similar all week. Because Cetus lies close to the celestial equator, it is visible from both the northern and southern hemispheres. In classical Greek mythology, Cetus represents the sea monster sent by Poseidon to ravage the kingdom of King Cepheus and Queen Cassiopeia, until the hero Perseus turned it to stone using the head of Medusa.
The constellation contains a true astronomical gem: Omicron Ceti, also known as Mira. This variable star rises and falls in brightness every 330 days or so, becoming invisible to the naked eye at its faintest. It is currently near its minimum, so observers should watch for it to return to visibility in the coming months.
