Indees, Sirius is the Latin form of the Greek Seirios meaning "scorcher". "Seirios kyon" is indeed the Dog
Star. Seirios is used as an adjective for the sun ("aktis seiria" = ray of sun)and of things that are warm ("seirion himation" = a light summer garment).
I could go in forever, but I'm sure you had enough :)