The Sun, known simply as such only within its own solar system, Primary, supplies energy for all life within the aforementioned system. It is a star which contains over 99% of the mass in the system, yet it is a relatively small star, in comparison.
Before word of Cradle's presence spread, the Sun was known as Pute-V (poot - VEE). Thanks to Cradians' brief galaxial outreach, other star-faring species have begun to know the star as Primary's Sun.