Presentation #102.293 in the session Poster Session.
The Transiting Exoplanet Survey Satellite (TESS) has given us extraordinary access to measure the physical sizes of some of the nearest exoplanets to the Sun. With careful and intensive radial-velocity follow-up campaigns, precise masses and densities for these planets can be measured, allowing a detailed study of planet formation and evolution to be performed. Worlds at the extremum of the distribution can allow an unprecedented window into the nature of planets, providing benchmark systems that can be used to better understand the underlying formation and evolutionary processes at play. Here we discuss our program to confirm some of the most extreme planetary systems, those worlds that are in and around the Neptune desert region. Our overall goal is to further study these confirmed systems photometrically and spectroscopically using instruments in Chile and in space, in order to probe planetary physics in a very detailed way. Part one of our TESS follow-up program primarily makes use of the Chiron, FEROS, and HARPS instruments to confirm the transiting planet candidates, whilst simultaneously measuring their masses and densities. Below we highlight a few of our most interesting systems, including the discovery and subsequent atmospheric investigation of the first ultrahot Neptune, LTT9779b, along with some of the shortest period planets that exist around the Neptune desert. These latest discoveries promise to allow detailed studies of the physical processes that drive this part of the planetary parameter space.