Cetus the Whale (or sea monster in ancient mythology) is the fourth largest constellation in the sky. This massive area sits south of the Sun’s elliptic and can be seen from every part of the Earth south of the Arctic Circle, although not necessarily in its entirety. Most of this giant equatorial constellation lies in the southern sky with a head that reaches up over the equator toward Aries.
The whale “swims” south of Pisces, the Fishes, with Eridanus, the river on one side and Aquarius, the Water Bearer on the other. The best time for viewing Cetus is in October. This large area of the sky is sprinkled with numerous notable objects including at least 14 stars with planets, numerous bright stars and deep sky objects, and three meteor showers.
The neighboring constellations are Aquarius, Aries, Eridanus, Fornax, Pisces, Sculptor, and Taurus.
Right Ascension: 01:42
Diameter (°): 34
Area (square °): 1231
Opposition: Oct 21
Size Rank: 4th
Brightness Rank: 31st
Major or notable stars in Cetus
Diphda (Deneb Kaitos) – β Ceti (Beta Ceti)
Menkar (Menkab) – α Ceti (Alpha Ceti)
Mira – ο Ceti (Omicron Ceti)
τ Ceti (Tau Ceti)
Baten Kaitos - ζ Ceti (Zeta Ceti)
Kaffaljidhma - γ Ceti (Gamma Ceti)
Mpingo - BD+00 316 The name was selected in the NameExoWorlds campaign by Tanzanian amateur astronomers in 2020
Felixvarela - BD-17 63 The name was selected in the NameExoWorlds campaign by Cuba
Axólotl. - HD 224693 The name was selected in the NameExoWorlds campaign by Mexico
Deep Sky Objects in Cetus
Messier 77 (M77, NGC 1068)
NGC 47 (NGC 58)
Mythology of the Constellation Cetus
The Cetus constellation is represented as a whale, chief monster of the deep, the largest of the aquatic race. It is fittingly a large constellation.
In ancient texts and drawings, it was not depicted looking like an actual whale we envision today. Instead, it can be seen as a fanged and fearsome creature from the sea. Its head extends from its body on a long neck, ready to gobble up its next victim.
The myth of Cetus is linked to the story of princess Andromeda, the daughter of Queen Cassiopeia and King Cepheus. Cassiopeia was very beautiful, stubborn and full of pride. Her biggest obsession was to become the most beautiful woman in the world, and she was super jealous of the Nereids nymphs.
Most writers consider this the famous sea monster who was sent by Neptune to gobble Andromeda up after her mother, Cassiopeia, bragged about how beautiful she was. Before Cetus could kill Andromeda, brave Perseus saved her by turning the sea monster to stone. At any rate, its true origin is buried somewhere in the mists of dark antiquity.
“The winged hero now descends, now soars,
And at his pleasure the vast monster gores.
Deep in his back, swift stooping from above.
His crooked sabre to the hilt he drove.”
It’s been established that this constellation had a place in the heavens long before Perseus. When the equinoctial sun in Aries (right over the head of Cetus) opened the year, it was nicknamed the “Preserver” or “Deliverer” by the idolaters of the East. According to Pausanias, this is why the sun was worshipped at Eleusis under the name of the “Preserver” or “Saviour”.