From Tar Valon Library
Author: Estyrien al'Halien
Celestin is an Aes Sedai of the Yellow Ajah. She sided with the Salidar Aes Sedai when the Tower split but was sent back to the Tower - along with nine other sisters, two from each Ajah except the Red and Blue - to spread dissent among the sisters there (CoT, Prologue).
Seaine and Pevara discovered the ten Salidar moles when questioning Zerah Dacan about the Black Ajah (TPoD, Ch. 26). They later told Yukiri, Saerin, and Doesine about the rebels. The five Sitters decided to use the moles to hunt the Black Ajah and forced each one to swear a personal oath of obedience on the Oath Rod (CoT, Prologue).