Quadratic phase forecasts for OGLE-LMC-LPV-40086 depend on the time split and baseline model

We test a steady frequency change as an explanation for poor fixed-period forecasts of the known red giant OGLE-LMC-LPV-40086. Early fits predict later public OGLE I photometry at three time splits. With two harmonics and all data, forecast gains over a fixed period are -11, 3 and -60 percent. An early offset changes the gains to 46, -25 and -431 percent. Thus an improved fit does not give a stable predictive drift in this scope. Later-only data, one-harmonic fits, two other known sources and sparse V measurements provide controls. Both bands use OGLE; independent instrument confirmation is absent. This is a restricted test of known long secondary period signals, not a new source or planet detection. Source measurements remain external. The bundle includes code, input hashes, aggregate results, a figure and retrieval steps.

astronomy · OGLE · long secondary periods · forecast validation · quadratic phase · instrumental artifacts · null result