The Evolution of Multiplanetary Systems With Misaligned USP Planets

Ultra-short period (USP) planets are exoplanets which orbit within the magnetic truncation gap of their respective star. There are several known systems in which the USP planet in a multi-planet system orbits misaligned to the plane of the outer planets. TESS offers a unique opportunity to observe a large number of transiting systems and find these misaligned planets. With this poster I explore the unique parameters of such a system, hoping to answer the question of how such a geometry comes about. I explore the relationship between the inclination of the USP planet and the quadrupole moment (J2) of the star TOI-125, investigating whether this relationship is parameter-dependent by comparing it with the misaligned system K2-266. I used the secular perturbation theory to assess this effect of J2on inclination and determine the planets’ eigenfrequencies. N-body simulations were also used to test how the misalignment changes with changing J2, as stars tend to “spin down” with age. I intend to derive a better understanding of systems with misaligned USP planets and how these parameters can occur. This will also help to expand our knowledge of how systems evolve with time through an ever decreasing J2.