Kaffaljidhma (Gamma Ceti) -- Double Star in Cetus
Double-Star in the Head of the Sea Monster
The constellation Cetus is often referred to as the Whale. But to me the ancient diagrams
of Cetus look more like a sea-monster with a back-end of a fish and the fore-limbs and
head of a dragon. Even more confusing is the name of the specular yellow and blue
double-star Gamma Ceti that is referred to as Kaffaljidhma. If I understand it correctly, the
five stars that make up the sea-monster’s head were in antiquity collectively call
Kaffaljidhma by Arab astronomers. This translates roughly to “the maimed, or part, or
stained hand”. How all this fits with a sea-monster’s head appears to be lost to history. Today,
Kaffaljidhma is assigned only to the star Gamma Ceti.
This yellow-white star with a bluish companion is an attractive sight in the telescope. Note
however, that the separation is only 1.9 arcseconds which means you will likely have to
use a high-power eyepiece to separate the pair. An accommodating stable atmosphere
is also a great help.
There is a third dim-star in the system that goes unseen by amateur astronomers. It is
separated from the primary star by 21,000 AU and takes 1.5 million years to complete