Speaker
Description
The formation and migration of hot Jupiters remain open questions in exoplanetary science. Their predominantly isolated architecture provides few direct clues about the dynamical processes responsible for placing giant planets on short-period orbits. Systems in which a hot Jupiter retains a close planetary companion are therefore particularly valuable, as gravitational interactions within such compact architectures can provide observational clues to their dynamical history. We report the characterisation of TOI-1811, a compact two-planet system containing the hot Jupiter TOI-1811 b on a 3.7-day orbit and a low-mass inner planet close to the 2:1 mean-motion resonance. Transit timing measurements reveal dynamical interactions between the two planets, thereby constraining the properties of the low-mass companion despite its shallow transits. TOI-1811 provides a rare example of a hot Jupiter embedded in a compact planetary system and demonstrates the potential of transit timing to uncover low-mass companions to giant planets. Its near-resonant architecture offers an important observational test of models for the formation and dynamical evolution of hot Jupiters.