One:The Adumbration of Byxs
When the three bodies are in syzygy with the sun, Byxs passes into the shadow of Xor.
The timing of the adumbrations is unpredictable. Some uneducated laypeople interpret adumbrations for purposes of divination. Certain superstitious persons have even suggested that the current age was brought into being by the action of Byxs, though natural philosophers reject such nonsense, pointing to the lack of a plausible mechanism of influence.
When by happy chance Byxs escapes the overlapping resonances of Xor and Motol, it falls into a semiperiodic pseudöoscillation, and the timing of its adumbrations can be predicted for some weddots in advance. Even then, observers of the adumbration can be hindered by weather, interference by other bodies, or by the adumbration falling on a high holiday.
Observing an adumbration of Byxs allows natural philosophers to infer the size and figure of Byxs, the size and figure of Xor, and the composition of the envelope of Xor. This latter question is hotly debated, and sadly its investigation is inaccessible to all but the few philosophers who possess the necessary equipment. Some scholars dispute even the existence of the envelope, denouncing supposed detections as the result of miscalibration and timing errors.