Constraints on the Kepler-36 system from Transit Timing Variations and new Radial Velocity data

We analyze new Radial Velocity data, in conjunction with Kepler data, to reassess the orbital parameters of the Kepler-36 system. 6 new RV measurements were taken by the Keck-HIRES spectrograph from September 21, 2021 to October 11, 2021. By carrying out differential evolution Markov Chain Monte Carlo-based analysis on the combined Transit Timing Variation and RV data, we determine improved orbital elements for the known planets in the system. A peak in the RV periodogram indicates a potential third planet in this system. We explore this possibility by comparing the Bayesian information criterion of the two-planet model of the Kepler-36 system to that of a three-planet model.