Binary system detection with BHEX depicting the total flux density of the source required to distinguish a binary from a single Gaussian source, assuming a thermal noise of 5 mJy/beam. The term w₁ is the angular diameter of the primary component. The y-axis describes the ratio between the primary and secondary component flux densities and solid angles. For illustrative purposes, we assumed the same brightness for both components of the binary system. The positions of the seven test cases presented below are labelled in this parameter space. Subscript A indicates the largest angular separation of the orbit from the observer’s perspective, and P is the smallest observed separation.