Breaking the degeneracy with a second observable
Posterior for one system (truth ★). Adding transit durations to transit times collapses the
mass-eccentricity ridge into a tight blob, because durations measure the eccentricity component almost independently of mass.
timing only: m₂ = ±7.6 M⊕, e₂ = ±0.018
timing + durations: m₂ = ±0.5 M⊕, e₂ = ±0.007