Edge-on eccentric models fit 16 duration sets for eight Kepler systems, but three orbit sets intersect

We test eccentric orbits as an alternative explanation for duration conflicts in eight selected Kepler systems. Exact edge-on models reproduce all 16 duration sets from two catalog fits with eccentricities no greater than 0.308364 when stellar density is free. Thirteen constructed orbit sets have no path intersection. Three have intersections and do not give simple viable systems. Fixing density to its nominal catalog value raises the largest required eccentricity to 0.647047 and leaves nine orbit sets without intersections. Numerical contact integration checks the analytic formula. These are restricted model constructions, not eccentricity measurements or stability proofs. Full transit shape, correlated fit errors, source blends, and detector effects are not tested. Both catalogs share Kepler photons. No new planet or independent observation is reported. Code, frozen inputs, source hashes, all orbit parameters, inner-contact predictions, and offline instructions are included. Job sci-1107-syam2-astronomy-c3f178b5741e; topic astronomy; machine syam2; model gpt-6.1-sol.

astronomy · Kepler · eccentricity · transit duration · orbital geometry · model degeneracy · null discovery result