Stars with Plumbing Issues: The Multi-component Ejecta of Common Envelopes
3D hydrodynamical simulations of Common-Envelope Evolution (CEE) for a 2 Msun star revealed that envelope ejection is not uniform but produces multi-component ejecta: a thick circumbinary disk and collimated bipolar outflows. These structures naturally reproduce key observational features seen in Water Fountains (WFs), suggesting CEE involves complex, non-spherical mass loss driven by angular momentum redistribution.