(Proposal ID) S16A-149 (PI) Jovanovic, Nemanja (Proposal Title) A high angular-resolution study of mass-loss in highly evolved stars (Abstract) Mass loss from stars in the last stages of life governs their ultimate destiny as a supernovae or planetary nebulae, and is crucial for galactic chemical enrichment. The mechanisms driving the mass loss remain poorly understood; to accelerate a dust-driven wind requires grains to form too close to the star, while aspherical and clumpy envelopes require an additional mechanism to shape the outflow, and multiple models have been proposed. In a continuation of our observing campaign begun in S2015B, we propose to observe a complementary set of targets which are only visible in Semester A, but which form a key subset of stars in our survey group. We will conduct simultaneous observations of evolved stars using coronagraphic NIR imaging (with SCExAO/HiCIAO) and visible, polarimetric interferometry using VAMPIRES. In observations led by the SCExAO and VAMPIRES teams, HiCIAO images will reveal the structure -- and hence mass- loss history -- in the envelopes of the objects. Simultaneously, VAMPIRES will provide diffraction-limited observations of the innermost circumstellar regions where the dust formation process takes place, and constrain dust grain properties using polarization -- helping solve the mystery of the wind driving mechanism and discriminate between competing models.