Light curve synthesis

In view of the ambiguity of the true orbital period of MT Ser two radically different models for MT Ser appear to be viable.

Model 1: Assuming the shorter of the two possible periods (P₁) to be correct, a reflection effect dominated model suggests itself, with the system consisting of a hot primary and a cooler secondary. The variations are caused by the phase dependent aspect of that side of the secondary star which is heated by the primary. Such a scenario leads to a single maximum and minimum per orbit. This is the model advocated by GB83.

Model 2: If P₂ is the correct period, two minima and maxima per orbit must be explained. This is best done by a model in which ellipsoidal variations dominate. Again, the system is considered to be composed of two components. However, in this case their relative temperatures or luminosities are not constrained a priori. The size of at least one and possibly both of the components is not small compared to its Roche lobe, leading to ellipsoidal deformations of its shape. The orbital variations are then due to the variable aspect of the deformed component(s), leading to two maxima and minima per orbit.

In the following, model calculations using the Wilson-Devinney code (Wilson & Devinney [1971], Wilson [1979]) will be analyzed in an attempt to discriminate between these two models.