The Whale or Sea Monster

Fully Visible:79°S – 65°N

In Greek mythology, King Cepheus and Queen Cassiopeia of Æthiopia (what we call the Upper Nile region) had a daughter named Andromeda. Cassiopeia boasted that she and her daughter was more beautiful than the Nereids, the sea nymphs who often accompanied Poseiden, god of the seas. As punishment, Poseiden sent a sea monster, Cetus, to ravage the coast of Æthopia. In desperation, Cepheus consulted an oracle who informed him that to appease Poseiden, Cepheus must sacrifice his daughter Andromeda to the sea monster. Thus, Andromeda was stripped naked and chained to the rocks on the coast of the sea. Fortunately for her, Perseus was passing by, having just slain the Gorgon, Medusa. He killed the sea monster and set Andromeda free, claiming her as his bride.

Although Cetus is not a member of the zodiac, the ecliptic passes close to the constellation boundary and thus, planets and asteroids frequently stray into this constellation.

The constellation of Cetus

Notable Features

Visible Named Stars
α Cet Menkar This star sometimes appears as Menkab or Keff al Djezma (from the Arabic al‑kaff al‑jadhmāʾ meaning 'the amputated hand') in older star atlases and catalogues.
β Cet Diphda This star sometimes appears as Deneb Kaitos (from the Arabic dhanab ul‑qayṭus ul‑janūbīyy meaning 'the southern branch of the tail of Cetus') in older star atlases and catalogues. In Chinese astronomy, this star is known as Tusikong, from Tŭ Sī Kōng meaning 'the master of constructions'.
γ Cet Kaffaljidhma This is a triple star system with a combined magnitude of +3.5.
ζ Cet Baten Kaitos This star appears as Rabah al Naamet (from the Arabic rabaʿ al‑naʿām meaning 'the fourth ostrich') in Mohammad Al Achsasi Al Mouakket's calendarium.
ο Cet Mira Mira was the first variable star discovered (in 1596) and is the prototype for long-period pulsating Mira variables. It varies between second and tenth magnitude over a cycle that is slightly less than a year.
Other Interesting Stars
τ Cet Although this star has no common name, it is one of the closest stars to the Sun and one of the few nearby stars that is visible to the naked eye.
BL Cet, UV Cet Although less than 9 light years from Earth, BL Cet is too faint to see with the naked eye. Its companion, UV Cet, is slightly closer but still can't be seen without a telescope. UV Cet is the prototype of the class of flare stars (variable stars which undergo unpredictable and dramatic increases of brightness over the space of a few minutes) called UV Ceti variables.
BD−17 63 Felixvarela This tenth-magnitude star is known to have at least one exoplanet. It is located near the star Diphda (β Cet).
HD 224693 Axólotl This eighth-magnitude star is known to have at least one exoplanet and is found near the border with Aquarius.
WASP‑71 Mpingo Found near the border with Pisces, this eleventh-magnitude star is known to have at least one exoplanet.
Deep Sky Objects
M77 This is a face-on spiral galaxy, only visible through a telescope. It is the brightest of a class of objects known as Seyfert galaxies, galaxies with active nuclei.
C51 IC 1613 is an irregular dwarf galaxy and a member of the Local Group of galaxies. To see it you must use a medium-size telescope.
C56 This is a planetary nebula and a small telescope is necessary to view it. Its New General Catalogue number is 246.
C62 This spiral galaxy is visible through a telescope. It is also known as NGC 247.
Meteor Shower Radiants
152 NOC Northern ω Cetids This minor daytime shower is active during early May.
153 OCE Southern ω Cetids This minor daytime shower is active at the same time as the northern branch.