Princeton University Thunch Talk

In order to understand a process as complex as planet formation, the most extreme cases are often the most revealing. At one extreme are the ultra-short-period planets (USP, orbital period <1 day), orbiting their host stars just a few stellar radii away. Thanks to their proximity to the host stars, USPs may represent our best chance of understanding the composition of small, Earth-like planets in the near future. Moreover, these highly irradiated worlds are great for studying the reflectivity/thermal emission from the rocky planets, the effect of photoevaporation, and possible planet-star magnetic interaction etc. In this talk, I will describe our recent works on the composition and orbital architecture of USP planets and the implication for their origin.