The Mega-MUSCLES Treasury Survey: Measurements of the Ultraviolet Spectral Chara

JWST will be able to observe the atmospheres of rocky planets transiting nearbyM dwarfs. A few such planets are already known (around GJ1132, Proxima Cen, andTrappist1) and TESS is predicted to find many more. Our MUSCLES Treasury Survey(Cycles 19+22) used Hubble/COS+STIS UV observations with contemporaneous Xrayand groundbased data to construct complete SEDs for 11 lowmass exoplanethosts. Here, we propose to expand the MUSCLES project to: (a) new M dwarfexoplanet hosts with varying properties; (b) reference M dwarfs below 0.3 solarmasses that may be used as proxies for M dwarf planet hosts; and (c) morerapidly rotating stars of GJ1132.s mass to probe XUV evolution over Gyrtimescales. We propose to gather the first panchromatic SEDs of rocky planet hosts GJ1132 and Trappist1. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]