"Hidden gems in the circumstellar envelopes of evolved stars"

As stars approach the end of their lives, they lose large amounts of mass, energy, and momentum through powerful stellar winds and outbursts. The ejection of these outflows has a profound impact on the star and its surroundings; thus, understanding it is crucial for both stellar and galactic evolution models. Indeed, the circumstellar environments of evolved stars are a tapestry of intricate structures, often adorned with shells, clumps, arcs, disks, jets and spirals. Detailed, multi-dimensional simulations together with exquisite multi-wavelength observations (e.g., with ALMA and JWST), are giving us new insights into the formation of these structures, and the underlying physical processes driving the outflows. In this talk I will discuss our studies of the interactions of stellar winds with the interstellar medium (e.g., for runaway and hypervelocity stars), and with nearby (sub-)stellar companions. I will also highlight the implications of our results for a wide range of phenomena, from stellar mass loss and mass transfer in binaries (e.g., symbiotic and related binary systems) to novae and interacting supernovae.