0 Assigned ID: 3382 ----- Attempting Submission 1 (Fri Mar 25 18:09:11 GMT 2022) ----- HST Phase I Proposal 3382 successfully submitted. Receipt: # 3382-1 ----- Attempting Submission 2 (Fri Mar 25 19:40:03 GMT 2022) ----- A vast amount--over 700 orbits--of Hubble time has been dedicated to characterizing the high energy radiation from M dwarfs over their lifetimes; one key goal is to understand exoplanet environments. The smallest M dwarfs are very different from Sun-like stars, with long pre-main sequence lifetimes and a higher fraction of their bolometric luminosity emitted at UV and X-ray wavelengths. Of critical importance to the next era of exoplanet science is connecting what we have learned from this vast library of HST spectra to the physics of planets themselves. Perhaps the highest impact observations in the first cycles of JWST will be the first measurements of planetary atmospheres around terrestrial planets, which are accessible only for planets orbiting the smallest stars. These atmospheres will be shaped by outgassing from the planet and atmospheric escape over billions of years. We propose a two-part effort: first, we will use archival HST UV spectra and X-ray data of 0.1-0.25 M_sun stars to model the high energy emission, creating reconstructed spectra of the currently-unobservable extreme ultraviolet (EUV). Next, we will use these reconstructed spectra as inputs to our atmospheric escape model for terrestrial planets, coupling the atmospheric escape driven by irradiation from the host star and the thermal emission of the planet, which controls outgassing rates. We will focus first on the atmospheres most amenable to JWST observations: warm Venus-like planets with CO2 atmospheres. We will digest the results of our models for observers, providing descriptions of which planets are most likely to have atmospheres and where new UV observations are most needed. PI Caroline Morley is an expert in modeling the atmospheres of exoplanets. Co-I Katie Teixeira is a first-year graduate student, working with PI Morley, who will develop the coupled thermal evolution and atmospheric loss model. Co-I Girish Duvvuri will develop the DEM modeling for these stars; he has previously published DEM analysis of the Sun and AU Mic, as well as a series of M dwarfs. Co-I Zach Berta-Thompson and Co-I J. Sebastian Pineda both have expertise in M dwarfs, including UV observations with HST. Co-Is Brad Foley and Cayman Unterborn are experts in geophysics, including the thermal evolution of rocky planets. Together, this team has the broad interdisciplinary knowledge about stellar spectroscopy/astrophysics, exoplanetary atmospheric modeling, and rocky planet evolution, to carry out this project. Exoplanets and Exoplanet Formation Stellar Physics and Stellar Types 0 Regular false false false true false false SUPPORTED