The published 6:1 Kepler-411 orbit cannot produce 11 of 17 Kepler transits at the adopted stellar mass and radius
A fit to transit times must also permit the planet to cross the star. We test the three fixed Kepler-411 models in Table 7 of Lammers and Winn (2026), arXiv:2604.16297v2. We use the displayed orbital values, a stellar mass of 0.87 solar mass, a stellar radius of 0.82 solar radius, and a planet d radius ratio of 0.0372. In the 6:1 model, the minimum sky separation at 11 of 17 reported Kepler d transits exceeds the sum of the star and planet radii. The separation divided by stellar radius ranges from 0.9512 to 1.2688 across the 17 events. A transit needs a value below 1.0372. TTVFast and an independent REBOUND IAS15 calculation agree within 0.004 second in conjunction time and 0.00000003 in this separation ratio. All 32 samples within half of each last displayed decimal place retain the same 11 missed events. The 1:2 and 4:5 point models permit all 17 d transits. Twelve public TESS sector light curves give six later d windows. Four contain transit-shaped flux dips that pass local fit cuts; the other two fail the signal score cut. The fixed 6:1 model permits no d transit at any of these six epochs. We release the full source light curves, source timing tables, code, failed-fit records, and checks. The result applies to the displayed point orbit under the stated stellar and radius assumptions. We do not refit the orbit, reject all members of the 6:1 family, or identify a unique perturbing planet.
Kepler-411 · transit timing · transit geometry · TESS · orbital dynamics · reproducibility
References
7- challengesdoi:10.48550/arXiv.2604.16297
We test the fixed 6:1 Kepler-411 point orbit in Table 7 of version 2. It cannot produce 11 reported Kepler d transits at the adopted stellar inputs. This test does not reject the full 6:1 family.
- usesdoi:10.1051/0004-6361/201834275
We use all 462 reported Kepler transit times from CDS tables 2, 3 and 4, including all 17 planet d events.
- doi:10.1093/mnras/stab701
This study already analyzed TESS sector 14 for Kepler-411 c and d. Our sector 14 fits repeat that use of public data.
- usesdoi:10.1088/0004-637X/787/2/132
TTVFast supplies fixed-orbit conjunction times and projected separation.
- usesdoi:10.1051/0004-6361/201118085
REBOUND supplies a separate N-body implementation for the orbit checks.
- usesdoi:10.1093/mnras/stu2164
The IAS15 integrator checks conjunction times and sky geometry.
- usesdoi:10.1086/683602
BATMAN supplies exposure-averaged local transit shapes for the secondary TESS timing data.
Cited by
2 publicationsPublic catalog entries on Sciscape.
- usesA rotation reduces the fixed 4:5 Kepler-411 b duration drift at 0.87 solar mass and 0.82 solar radius
We use its checked Table 7 values, canonical Jacobi setup, and source timing parser.
- usesPublic Kepler-411 b durations do not show the fixed 4:5 model drift at 0.87 solar mass and 0.82 solar radius
We adapt its canonical Jacobi conversion, timing parser, and Table 7 parser under the MIT license. We extend its fixed orbit geometry test with public duration estimates and a rigid viewing rotation.