Delaya was so close to Alderaan that it was clearly visible in Alderaan's sky. Alderaan outsourced much of its industry to Delaya, creating a planet with a large population and many urban areas filled with factories and warehouses as well as homes. Delaya's busy economy attracted workers from many species, including Bothans, Besalisk, Ryn, and Humans. After the destruction of Alderaan, Delaya was the only planet in the system that supported life. It was significantly smaller than Alderaan.
SenatorBail Antilles was responsible for passing laws that facilitated trade between the two planets in 33 BBY.
Carlist Rieekan was inspecting a new Rebel Alliancesatellite transmission station in a far orbit around Delaya when Alderaan was destroyed. Delaya served as an evacuation site for some of the few who escaped Alderaan before its destruction.
When PrincessLeia Organa visited Delaya to formally mourn her homeworld along with the refugees from it as well as to garner support for the Rebel Alliance, she enountered the former Jedi Ferus Olin, as well as a group of Alderaanians who tried to turn her in to the Galactic Empire.