The Kepler-90 (K90) system exhibits the greatest multiplicity (8) of planets found to date. All eight planets transit and were discovered by the NASA Kepler primary mission. The two outermost planets, g (P = 211 d) and h (P = 332 d), exhibit significant transit-timing variations, but were only observed 6 and 3 times respectively by Kepler. To determine masses and orbital properties for planets g and h, we combined 34 radial velocities (RVs) of K90 collected over a decade with the Kepler data. We jointly modeled the transit times of planets g and h and the RV time series, then used our two-planet model to predict their future times of transit. These predictions led us to recover a transit of K90g with ground-based observatories in May 2024. We then combined the 2024 transit and several previously unpublished transit times of planets g and h with the Kepler transits and RV data to update the masses and linear ephemerides of the planets, finding Mg = 15.0 ± 1.3 M⊕, and Mh = 203 ± 16 M⊕. These results enable further insights into the K90 system and pave the way for atmospheric characterization with space-based facilities.
| Subject : | : | Oral presentation |
| Topics | : | Planetary systems, architecture and dynamics |
| PDF version | : |  PDF version |
