0 Assigned ID: 3621 ----- Attempting Submission 1 (Fri Mar 25 22:04:30 GMT 2022) ----- HST Phase I Proposal 3621 successfully submitted. Receipt: # 3621-1 ----- Attempting Submission 2 (Fri Mar 25 23:35:45 GMT 2022) ----- We propose to adapt an existing modeling framework to interpret ultraviolet observations of atmospheric escape in exoplanets, aiming to provide the community with a scalable, open-source code that will be used to understand the evolution of exoplanets at the population level. Our motivation lies in that understanding the complex evolution of planetary atmospheres and how they respond to a changing space environment is a critical factor in the search for Earth-like worlds. Most of the exoplanets discovered to date orbit extremely close to their host stars, driving their atmospheres to quickly evaporate to space. Recent transmission spectroscopy observations of atmospheric escape in several hot exoplanets have sparked a new wave of theoretical efforts in modeling photoevaporation and its impacts in the evolution of hot gas giants to rocky planets. As more and more observations are executed, we need to develop simplified theoretical frameworks that allow us to effectively probe exoplanet atmospheres as a sample, which in turn allows us to perform comparative studies. The code we propose to develop allows for fast calculations that yield Bayesian estimates of mass loss rates and other properties of the planet's upper atmosphere. HST has already observed more than 10 exoplanets in the UV using the transmission spectroscopy technique, and several other planets are slated to be observed in Cycle 29. At the end of the project, we will leverage these archival and future datasets to uniformly study all observed planets using this new framework, yielding for the first time a comparative study of photoevaporation in exoplanets based on HST data. The Principal Investigator L. dos Santos has previously led and participated in several HST programs to pin down the high-energy environment and atmospheric escape rates of exoplanets and specializes in transmission spectroscopy techniques for transiting exoplanets, as well as modeling of planetary outflows. Dos Santos has an extensive experience in analyzing UV transit spectroscopy datasets obtained with HST, as demonstrated in Dos Santos et al. (2019, 2020a, b, 2021). The PI is also the main developer of the open-source code p-winds (Dos Santos et al. 2022), which will be expanded to include chemical species relevant for HST. A. Vidotto is a leading expert who specializes in simulating the space weather and stellar wind interactions of exoplanet upper atmospheres using hydrodynamical models, whose work has extensively been used to interpret HST observations. S. Vissapragada has led studies of metastable He narrowband photometry in hot Jupiters, and developed theoretical frameworks to interpret them in the context of atmospheric escape. L. Dos Santos will lead the development necessary for the code, with contributions from S. Vissapragada, who has already made many contributions to the p-winds code. A. Vidotto will provide the theoretical support necessary for the development. Exoplanets and Exoplanet Formation 0 Regular false false true true false false SUPPORTED