Seminar

Located about 39 light-years away from the Earth, the TRAPPIST-1 system consists of a very-low mass 8-billion-year-old star and seven Earth-sized planets on close-in orbits. The innermost planet orbits the star in a mere 1.5 days while the outermost completes an orbit in 19 days. More interestingly, each adjacent planet pair in the system has orbital periods that are near simple integer ratios such as 3:2 and 4:3, forming a rare dynamical configuration known as a resonant chain. As the planets in this system are closely-packed, it is natural to question the stability of the system in the long run. The primary focus of this work is to study the dynamics of the TRAPPIST-1 system to understand the factors contributing to its stability for billions of years. In addition, a model system in which all the planets are in mean motion resonances is also constructed and the orbital eccentricities of the planets derived from the model is compared to the orbital eccentricities derived from the observational data.