Yes, the angle of eternity. That's how I know it's coming. How else can I make the prediction?
Aughra uses this device, a "triangulum", to explain the Great Conjunction to Jen. It is representation of the Great Conjunction, showing the Eye of the superimposed suns, seen through the greater triangle that is the roof portal of the castle of the urSkeks.
In a system with three suns, astronomical calculations would be extremely complex. Therefore, Aughra's astronomy is devised chiefly through intuition and empirical models. This is but one of the many bits of alchemical equipment, astrolabes and other scientific devices scattered throughout her observatory, that Aughra employs to make her predictions.