the myth behind the cancer constillation is a crab
There can be no myth because Polaris is not a constellation!
Maybe
Cygnus is a Swan.
apollos son died and the king went down to the river bottom every day. He went down there so often, that he turned into a swan
Cygnus is not a constellation of the zodiac.
Cygnus is Latin for swan.
cygnus mean swan
The name of the constellation is cygnus.
The swan is associated with the myth of Leda. Cygnus is Latin for Swan, with Cygnet ( sounds like Signet, which is a publisher!) an immature one of the type favored by Mr. Anderson.
It is the Story of Hades and Persephone.
genus cygnus