Princeton University Extrasolar Planet Discussion Group

Convergent disk migration has long been suspected to be responsible for forming planetary systems with a chain of mean-motion resonances (MMR). Dynamical evolution over time could disrupt the delicate resonant configuration. We present TOI-1136, a 700-Myr old G star with 6 transiting planets in mean-motion resonances. The orbital period ratios deviate from exact commensurability by only a few parts in10^-4, smaller than the deviations of 10^-2 seen in mature Kepler near-resonant systems. TOI-1136 appears to be a pristine example of the orbital architecture emerging from convergent disk migration before dynamical processes disrupt the resonance. The resonant chain also contains a very delicate 7:5 resonance 2nd order resonance that favors gentle Type-I migration in a low density disk with an inner edge at about 0.05AU.