Exotrojan TTV limits in hot Jupiter systems

We derived transit times and assessed the compatibility of TTV residuals with co-orbital models through N-body simulation using the REBOUND N-body code. Accounting for the physical degeneracy between Trojan mass and libration amplitude, we placed upper mass limits on possible companions for typical libration amplitudes. For a typical libration amplitude of 15{deg}, we rule out exotrojans more massive than 1 Earth mass in 130 systems (~50% of our sample).

A more conservative chi^2^ analysis incorporating observational uncertainties places this limit at 3 Earth masses. Additionally, we used the stability boundaries of the 1:1 resonance to exclude dynamically unstable configurations, ensuring our derived mass limits fall within the stable regime. Our results provide stringent constraints on co-orbital formation in short-period systems and establish a framework for future high-precision missions such as the PLAnetary Transits and Oscillations of stars (PLATO) or Earth 2.0 (ET) mission.