Physical origin of Ansky’s secular period increase

Determine the physical origin of the persistent recurrence-period increase observed in the QPE source Ansky, which has a positive period derivative inconsistent with orbital decay from purely dissipative processes.

Background

The paper describes Ansky as a QPE source whose recurrence period increased from approximately 4.5 to 10 days and later reached approximately 14 days, with a measured positive period derivative. This behavior contrasts with the period decrease expected from gas drag and gravitational-wave emission in recurrent disk-crossing scenarios. Although the proposed satellite-black-hole–disk-transit model can reproduce Ansky’s flare duration and delayed UV counterpart for suitable instantaneous parameters, the broader physical origin of Ansky’s secular timing evolution remains unresolved.