The Krillian Star System is a portion of space originally held by the Delphian Empire prior to the Battle of Cimtar that devastated the Twelve Colonies.
This star system contains one known planet, Gamoray, which was slated to become an "outer capitol" for the Cylon Empire. This is also the star system that Pegasus stayed within, attacking the Cylon occupied planet to obtain fuel and needed supplies (TOS: "The Living Legend, Part I").