This week, observers can locate Cetus, a sprawling constellation often depicted as a whale or sea monster. Though faint, Cetus occupies a vast 1,230 square degrees of the sky, making it the fourth largest of the 88 modern constellations. Its size, combined with its dim stars, makes it a subtle but rewarding target for stargazers.
Visibility and Location
Cetus is conveniently positioned near the celestial equator, meaning it’s visible from both the Northern and Southern Hemispheres. Current charts show the view from London on November 17th at 20:00 GMT, but the constellation’s position remains relatively stable throughout the week. Look south-southeast to trace its faint outline.
Mythological Origins
The constellation’s name and imagery come from Greek mythology. Cetus was a fearsome sea monster dispatched by Poseidon to punish the kingdom of King Cepheus and Queen Cassiopeia. To save their daughter Andromeda, the hero Perseus famously turned the beast to stone using the head of the gorgon Medusa. This tale underscores how ancient cultures linked celestial patterns to their myths and legends.
Mira: A Variable Star Within Cetus
Cetus contains one notable astronomical feature: Omicron Ceti, also known as Mira. This is a pulsating variable star with a dramatic cycle. Every 332 days, Mira swells in brightness, becoming easily visible to the naked eye, before fading back into obscurity. Currently, Mira is near its faintest point, but observers should monitor it in the coming months as it brightens again.
The cyclical brightening and dimming of Mira was one of the first variable stars discovered, and its behavior helped scientists understand stellar evolution. Observing Mira provides a tangible connection to the dynamic nature of the universe.
Cetus, despite its faintness, offers a blend of mythology and astronomy. Whether tracing the outline of the sea monster or watching for the fluctuations of Mira, this constellation provides a quiet yet compelling glimpse into the night sky
