Modeling of TLC variability for an analogue of Kepler-15b with a prescribed precessing ring: panel a: model image of the transiting exoplanet with a precessing ring (solid line shows the trajectory of planet). Panel b: variations of the shape parameter A_s of the simulated synthetic TLC. Panel c: variations of the simulated transit duration Δt_e − Δt_s. Panel d: variations of the simulated transit depth ΔF_tr. Panel e: variations of the simulated TLC minimum time Δt_m. Panel f: variations of the simulated transit start-time Δt_s. Panel g: variations of the simulated transit end-time Δt_e. The abscissascale ΔJD = JD − 2 454 833.0 is in Julian days (JD).