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AR 17035 (Archival Research)

Sun Jul 14 11:54:36 GMT 2024

Principal Investigator: Leonardo Dos Santos
PI Institution: Space Telescope Science Institute
Investigators (xml)

Title: The Great Escape: A comparative study of photoevaporation in exoplanets observed with HST
Cycle: 30

Abstract
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.