Abstract

I will discuss the challenges of modeling exoplanet data consistent with multiple-planet systems, focusing on the gravitational interactions and resulting transit time variations (TTVs) and deviations from multi-keplerian RV predictions. These dynamical signals provide valuable information about the orbital architecture and dynamical masses of exoplanets. I will highlight recent TTVs discoveries made by TESS , specifically warm giant-mass pairs near a 2:1 mean motion resonance (MMR). To aid in detailed analysis of transit and Doppler data, astrometry, and spectral line activity analysis, I will also demonstrate the free, fast, and powerful Exo-Striker GUI exoplanet toolbox. Exo-Striker offers a wide range of tools, including Keplerian and dynamical modeling of multi-planet systems, MCMC and nested sampling, Gaussian Processes modeling, N-body long-term stability checks of multi-planet systems, MMR analysis, fast interactive plotting, and the ability to export LaTeX tables with best-fit parameters, errors, and statistics. Additionally, Exo-Striker provides access to the RVBank database, which contains over 300,000 unique RVs and activity indices from HARPS and HIRES . With a combination of Fortran efficiency and Python flexibility, Exo-Striker is cross-platform compatible (MAC OS, Linux, Windows) and easy to use.