I need a mirrorless camera, and lenses, that's decent for landscapes as well as some night sky milky way / exposure shots without a tripod (i.e, good stabilization). I'd like something lightweight, compact, weatherproof and good battery life (or chargeable via USB).

I'm buying used, and would like to spend no more than $600 on the camera, so I can afford some room for lenses. I'm considering the Olympus OM-D E-M1 II due to some articles I saw that used it for both milky way exposures and landscapes, and it's cheap af.