Study of 2004 VC₁₃₁. The Lomb periodogram (plot a)) has one main peak, suggesting a rotational period of 2 × 7.85 hr (plot b)). The rotational phase of the light curve is between 0 and 2, and so two rotations are plotted. With plots (c) and (d), we calculated the potential mass ratios, size, and shape of the components, density, and separation (D) for a contact binary configuration.