Observability conditions for Venus’co-orbitals from the Rubin Observatory site over 2020–2036. The left panels show the known co-orbital 2020 CL1, while the right panels show the fictitious object (fic3). Upper panels display the apparent magnitude variations, with the horizontal dashed line indicating Rubin Observatory single-visit detection limit of 23.5. Lower panels show elevation above the horizon, where the dashed line marks the 20^◦ minimum elevation required for effective observations.